diff --git a/.gitignore b/.gitignore
index 5881234..afcf7ab 100644
--- a/.gitignore
+++ b/.gitignore
@@ -419,6 +419,12 @@ FodyWeavers.xsd
 !/vendor/webview2/arm64
 !/vendor/webview2/arm64/**
 
+# Vendored ARM64 devcon.exe — same explicit un-ignore (the arm64/ rule above
+# otherwise catches it). The x64 devcon at vendor/devcon/devcon.exe is tracked
+# directly; the ARM64 build stages this copy into bin\Release-ARM64\drivers\.
+!/vendor/devcon/arm64
+!/vendor/devcon/arm64/**
+
 # Local-only planning and notes — kept on disk for context, not pushed.
 /docs/
 
diff --git a/AppSandbox.sln b/AppSandbox.sln
index e1ac8b5..43906af 100644
--- a/AppSandbox.sln
+++ b/AppSandbox.sln
@@ -178,6 +178,7 @@ Global
 		{0FA17E55-9C3D-4B21-AE60-5D7C1B2E3F40}.Release|ARM64.ActiveCfg = Release|ARM64
 		{0FA17E55-9C3D-4B21-AE60-5D7C1B2E3F40}.Release|x64.ActiveCfg = Release|x64
 		{0FA17E55-9C3D-4B21-AE60-5D7C1B2E3F40}.Release|x64.Build.0 = Release|x64
+		{0FA17E55-9C3D-4B21-AE60-5D7C1B2E3F40}.Release|ARM64.Build.0 = Release|ARM64
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
diff --git a/Directory.Build.props b/Directory.Build.props
index d477a4d..104a162 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -33,4 +33,19 @@
   <PropertyGroup Condition="'$(BuildingInsideVisualStudio)' != 'true'">
     <SkipPackageVerification>true</SkipPackageVerification>
   </PropertyGroup>
+
+  <!--
+    Same class of problem as the InfVerif skip above, for ARM64 driver builds.
+    ARM64 drivers must be Universal, so the WDK runs ApiValidator on them — but it
+    defaults to the x86 ApiExtractor (aitstatic.exe), which cannot read an ARM64 PE
+    and fails with exit code 193 (ERROR_BAD_EXE_FORMAT) when cross-building ARM64 on
+    a non-ARM64 host (e.g. the x64 dev/CI box). Disable it ONLY for that cross-build
+    case: native ARM64 hosts and every x64 build still run it, and Microsoft re-runs
+    full API validation on every attestation submission, so nothing ships unchecked.
+    (Checks both PROCESSOR_ARCHITECTURE and ...ITEW6432 so an emulated x64 MSBuild on
+    an ARM64 host is correctly treated as "host can validate".)
+  -->
+  <PropertyGroup Condition="'$(Platform)' == 'ARM64' And '$(PROCESSOR_ARCHITECTURE)' != 'ARM64' And '$(PROCESSOR_ARCHITEW6432)' != 'ARM64'">
+    <ApiValidator_Enable>false</ApiValidator_Enable>
+  </PropertyGroup>
 </Project>
diff --git a/src/backend_win/d3dlayers.c b/src/backend_win/d3dlayers.c
index ccd66ee..66f4bfa 100644
--- a/src/backend_win/d3dlayers.c
+++ b/src/backend_win/d3dlayers.c
@@ -7,8 +7,8 @@
  *   2. Windows Update FE3 client protocol over WinHTTP (HTTPS):
  *        GetCookie -> SyncUpdates(filtered by WuCategoryId)
  *                  -> GetExtendedUpdateInfo2 -> time-limited CDN url.
- *      The x64 package is located by identifier in the response, so version
- *      changes / extra updates do not break resolution.
+ *      The package for the build architecture is located by identifier in the
+ *      response, so version changes / extra updates do not break resolution.
  *   3. Download the .appx (a zip) from the Microsoft CDN.
  *   4. Extract with the in-box tar.exe (libarchive handles zip natively).
  *   5. Copy the mapping-layer files into <exe_dir>\d3dlayers\ (cached).
@@ -36,17 +36,33 @@
 #define DL_FE3_PATH_SECURED L"/ClientWebService/client.asmx/secured"
 #define DL_SOAP_HEADERS     L"Content-Type: application/soap+xml; charset=utf-8\r\n"
 #define DL_CACHE_SUBDIR     L"d3dlayers"
-#define DL_APPX_NAME        L"D3DMappingLayers_x64.appx"
+/* The D3D Mapping Layers Store package ships a per-architecture .appx; pick the
+   one matching the guest (= build) architecture. The host downloads it, so on
+   the ARM64 build we fetch and stage the arm64 layers for the arm64 guest. */
+#if defined(_M_ARM64)
+#  define DL_ARCH        L"arm64"
+#  define DL_ARCH_A       "arm64"
+#else
+#  define DL_ARCH        L"x64"
+#  define DL_ARCH_A       "x64"
+#endif
+#define DL_APPX_NAME    L"D3DMappingLayers_" DL_ARCH L".appx"
+/* Substring identifying the package file in the SyncUpdates response — the
+   InstallerSpecificIdentifier contains e.g. "..._x64_..." / "..._arm64_...". */
+#define DL_ISI_ARCH      "_" DL_ARCH_A "_"
 #define DL_MAX_ROUNDS       5   /* FE3 faults intermittently; retry the chain */
 
-/* Files to extract: dest leaf name <- source path inside the .appx. */
+/* Files to extract: dest leaf name <- source path inside the .appx. The arch
+   subfolder inside the package (x64\ / arm64\) is selected by DL_ARCH; the
+   Vulkan ICD manifest is staged under the arch-neutral name dzn_icd.json so the
+   guest agent references one fixed filename regardless of architecture. */
 static const wchar_t *const DL_DST[] = {
     L"OpenGLOn12.dll", L"dxil.dll", L"OpenCLOn12.dll",
-    L"clon12compiler.dll", L"vulkan_dzn.dll", L"dzn_icd.x64.json"
+    L"clon12compiler.dll", L"vulkan_dzn.dll", L"dzn_icd.json"
 };
 static const wchar_t *const DL_SRC[] = {
-    L"x64\\OpenGLOn12.dll", L"x64\\dxil.dll", L"x64\\OpenCLOn12.dll",
-    L"x64\\clon12compiler.dll", L"x64\\vulkan_dzn.dll", L"dzn_icd.x64.json"
+    DL_ARCH L"\\OpenGLOn12.dll", DL_ARCH L"\\dxil.dll", DL_ARCH L"\\OpenCLOn12.dll",
+    DL_ARCH L"\\clon12compiler.dll", DL_ARCH L"\\vulkan_dzn.dll", L"dzn_icd." DL_ARCH L".json"
 };
 #define DL_NFILES ((int)(sizeof(DL_DST)/sizeof(DL_DST[0])))
 
@@ -318,10 +334,10 @@ done:
 
 /* ---- response parsing ---- */
 
-/* Find the x64 D3DMappingLayers .appx in a (decoded) SyncUpdates response and
- * resolve its UpdateIdentity by joining the file's enclosing <Update> <ID> to
- * the matching NewUpdates <UpdateInfo> <UpdateIdentity>. */
-static BOOL parse_x64_leaf(const char *buf, char *uid, size_t uid_cch,
+/* Find the D3DMappingLayers .appx matching the build architecture in a
+ * (decoded) SyncUpdates response and resolve its UpdateIdentity by joining the
+ * file's enclosing <Update> <ID> to the matching NewUpdates <UpdateIdentity>. */
+static BOOL parse_leaf(const char *buf, char *uid, size_t uid_cch,
                            char *rev, size_t rev_cch, char *digest, size_t dig_cch)
 {
     const char *p = buf;
@@ -340,11 +356,11 @@ static BOOL parse_x64_leaf(const char *buf, char *uid, size_t uid_cch,
             !attr_in(tag, "InstallerSpecificIdentifier", isi, sizeof(isi))) {
             p = gt + 1; continue;
         }
-        if (!strstr(isi, "D3DMappingLayers") || !strstr(isi, "_x64_") ||
+        if (!strstr(isi, "D3DMappingLayers") || !strstr(isi, DL_ISI_ARCH) ||
             !strstr(fn, ".appx")) {
             p = gt + 1; continue;
         }
-        /* matched the x64 package file */
+        /* matched the package file for this architecture */
         attr_in(tag, "Digest", digest, dig_cch);
 
         /* nearest <ID>N</ID> before this <File> = the ExtendedUpdateInfo id */
@@ -404,7 +420,7 @@ static BOOL parse_file_url(const char *buf, const char *digest,
     return FALSE;
 }
 
-/* Resolve the x64 package CDN url from Microsoft. Returns 0 on success. */
+/* Resolve the (build-architecture) package CDN url from Microsoft. Returns 0 on success. */
 static int resolve_url(const char *wucatid, wchar_t *url_out, size_t url_cch)
 {
     int round, rc = -1;
@@ -438,8 +454,8 @@ static int resolve_url(const char *wucatid, wchar_t *url_out, size_t url_cch)
         if (t1) { sync_req = str_replace_all(t1, "%CATID%", wucatid); free(t1); }
         if (sync_req) { sync_resp = fe3_post(DL_FE3_PATH, sync_req); free(sync_req); }
         if (sync_resp) html_unescape(sync_resp);
-        if (!sync_resp || !parse_x64_leaf(sync_resp, uid, sizeof(uid), rev, sizeof(rev),
-                                          digest, sizeof(digest))) {
+        if (!sync_resp || !parse_leaf(sync_resp, uid, sizeof(uid), rev, sizeof(rev),
+                                      digest, sizeof(digest))) {
             free(sync_resp); Sleep(1500); continue;
         }
         free(sync_resp);
@@ -462,7 +478,7 @@ static int resolve_url(const char *wucatid, wchar_t *url_out, size_t url_cch)
     return rc;
 }
 
-/* The shipped dzn_icd.x64.json gives library_path as "x64\vulkan_dzn.dll",
+/* The shipped dzn_icd.<arch>.json gives library_path as "<arch>\vulkan_dzn.dll",
  * relative to the manifest. The layers are staged into one flat directory, so
  * point library_path at the DLL's fully-qualified location in the guest.
  *
@@ -479,7 +495,7 @@ static void rewrite_dzn_json(const wchar_t *dir)
     char *buf, *fixed;
     size_t rd;
 
-    swprintf_s(path, MAX_PATH, L"%s\\dzn_icd.x64.json", dir);
+    swprintf_s(path, MAX_PATH, L"%s\\dzn_icd.json", dir);
     if (_wfopen_s(&f, path, L"rb") != 0 || !f) return;
     fseek(f, 0, SEEK_END); sz = ftell(f); fseek(f, 0, SEEK_SET);
     if (sz <= 0 || sz > 65536) { fclose(f); return; }
@@ -489,10 +505,10 @@ static void rewrite_dzn_json(const wchar_t *dir)
     fclose(f);
     buf[rd] = 0;
 
-    /* On disk the JSON value is the 18 bytes  x64\\vulkan_dzn.dll  (two
-     * backslash characters, JSON-escaped). Match that exactly and replace it
-     * with the absolute guest path (each backslash JSON-escaped). */
-    fixed = str_replace_all(buf, "x64\\\\vulkan_dzn.dll",
+    /* On disk the JSON value is  <arch>\\vulkan_dzn.dll  (two backslash
+     * characters, JSON-escaped). Match that exactly and replace it with the
+     * absolute guest path (each backslash JSON-escaped). */
+    fixed = str_replace_all(buf, DL_ARCH_A "\\\\vulkan_dzn.dll",
                             "C:\\\\Windows\\\\AppSandbox\\\\d3dlayers\\\\vulkan_dzn.dll");
     free(buf);
     if (!fixed) return;
diff --git a/src/backend_win/d3dlayers.h b/src/backend_win/d3dlayers.h
index 41c5588..69222b5 100644
--- a/src/backend_win/d3dlayers.h
+++ b/src/backend_win/d3dlayers.h
@@ -14,7 +14,8 @@
  *   OpenCLOn12.dll      OpenCL -> D3D12
  *   clon12compiler.dll  OpenCL compiler backend
  *   vulkan_dzn.dll      Vulkan (Mesa Dozen) -> D3D12
- *   dzn_icd.x64.json    Vulkan ICD manifest (points at vulkan_dzn.dll)
+ *   dzn_icd.json        Vulkan ICD manifest (points at vulkan_dzn.dll); staged under
+ *                       this arch-neutral name from the package's dzn_icd.<arch>.json
  */
 
 #ifndef D3DLAYERS_H
diff --git a/src/backend_win/disk_util.c b/src/backend_win/disk_util.c
index 1d2916d..7f22096 100644
--- a/src/backend_win/disk_util.c
+++ b/src/backend_win/disk_util.c
@@ -15,8 +15,27 @@
 
 #include <urlmon.h>
 
-#define SSH_MSI_URL     L"https://github.com/PowerShell/Win32-OpenSSH/releases/download/10.0.0.0p2-Preview/OpenSSH-Win64-v10.0.0.0.msi"
-#define SSH_MSI_NAME    L"OpenSSH-Win64-v10.0.0.0.msi"
+/* Architecture token written into every autounattend/unattend component's
+   processorArchitecture attribute. Matches the guest, which is the build arch
+   (see ASB_IS_ARM64 in disk_util.h). */
+#if ASB_IS_ARM64
+#  define ASB_UA_ARCH   L"arm64"
+#else
+#  define ASB_UA_ARCH   L"amd64"
+#endif
+
+/* OpenSSH Server MSI, staged into the guest and installed by SetupComplete.cmd.
+   The Win32-OpenSSH release ships a per-architecture MSI; pick the one matching
+   the guest (= build) architecture so it installs on an ARM64 guest. */
+#if ASB_IS_ARM64
+#  define SSH_MSI_URL     L"https://github.com/PowerShell/Win32-OpenSSH/releases/download/10.0.0.0p2-Preview/OpenSSH-ARM64-v10.0.0.0.msi"
+#  define SSH_MSI_NAME    L"OpenSSH-ARM64-v10.0.0.0.msi"
+#  define SSH_MSI_NAME_A   "OpenSSH-ARM64-v10.0.0.0.msi"  /* narrow, for the cmd scripts */
+#else
+#  define SSH_MSI_URL     L"https://github.com/PowerShell/Win32-OpenSSH/releases/download/10.0.0.0p2-Preview/OpenSSH-Win64-v10.0.0.0.msi"
+#  define SSH_MSI_NAME    L"OpenSSH-Win64-v10.0.0.0.msi"
+#  define SSH_MSI_NAME_A   "OpenSSH-Win64-v10.0.0.0.msi"  /* narrow, for the cmd scripts */
+#endif
 
 static const GUID VHDX_VENDOR_MS = {
     0xec984aec, 0xa0f9, 0x47e9,
@@ -212,6 +231,32 @@ static const wchar_t *lang_to_input_locale(const wchar_t *lang)
     return L"0409:00000409";  /* fallback */
 }
 
+#if ASB_IS_ARM64
+/* Emit RunSynchronousCommand entries (inside an already-open <RunSynchronous>)
+   that disable the Windows 11 setup hardware requirement checks by writing the
+   HKLM\SYSTEM\Setup\LabConfig bypass keys. ARM Windows HCS exposes no vTPM, so
+   without these Windows Setup's appraiser would refuse to install. `order` is
+   the next <Order> value to use; returns the order after the last entry.
+   ARM-only: on x64 the guest gets a real vTPM from HCS and needs no bypass. */
+static int write_tpm_bypass_commands(FILE *f, int order)
+{
+    static const wchar_t *const keys[] = {
+        L"BypassTPMCheck", L"BypassSecureBootCheck", L"BypassRAMCheck",
+        L"BypassStorageCheck", L"BypassCPUCheck"
+    };
+    int i;
+    for (i = 0; i < (int)(sizeof(keys) / sizeof(keys[0])); i++) {
+        fwprintf(f,
+            L"                <RunSynchronousCommand wcm:action=\"add\">\n"
+            L"                    <Order>%d</Order>\n"
+            L"                    <Path>reg add HKLM\\SYSTEM\\Setup\\LabConfig /v %s /t REG_DWORD /d 1 /f</Path>\n"
+            L"                </RunSynchronousCommand>\n",
+            order++, keys[i]);
+    }
+    return order;
+}
+#endif
+
 /* Generate autounattend.xml with credentials and VM name substituted.
    If is_template, adds SecureStartup-FilterDriver to disable BitLocker
    (required for sysprep). */
@@ -238,7 +283,7 @@ static BOOL generate_autounattend(const wchar_t *output_path,
         L"\n"
         L"    <settings pass=\"windowsPE\">\n"
         L"        <component name=\"Microsoft-Windows-International-Core-WinPE\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <SetupUILanguage><UILanguage>%s</UILanguage></SetupUILanguage>\n"
@@ -248,7 +293,7 @@ static BOOL generate_autounattend(const wchar_t *output_path,
         L"            <UserLocale>%s</UserLocale>\n"
         L"        </component>\n"
         L"        <component name=\"Microsoft-Windows-Setup\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <UserData>\n"
@@ -274,19 +319,32 @@ static BOOL generate_autounattend(const wchar_t *output_path,
         L"                    <ModifyPartition wcm:action=\"add\"><Order>2</Order><PartitionID>2</PartitionID></ModifyPartition>\n"
         L"                    <ModifyPartition wcm:action=\"add\"><Order>3</Order><PartitionID>3</PartitionID><Format>NTFS</Format><Label>Windows</Label><Letter>C</Letter></ModifyPartition>\n"
         L"                </ModifyPartitions>\n"
-        L"            </Disk></DiskConfiguration>\n"
+        L"            </Disk></DiskConfiguration>\n",
+        lang, lang_to_input_locale(lang), lang, lang, lang);
+
+    /* ARM only: disable the Windows 11 Setup hardware checks via the
+       HKLM\SYSTEM\Setup\LabConfig keys, from a windowsPE RunSynchronous in the
+       Setup component (runs before the appraiser). ARM Windows HCS has no vTPM,
+       so Setup would otherwise refuse to install. */
+#if ASB_IS_ARM64
+    fwprintf(f, L"            <RunSynchronous>\n");
+    write_tpm_bypass_commands(f, 1);
+    fwprintf(f, L"            </RunSynchronous>\n");
+#endif
+
+    fwprintf(f,
         L"        </component>\n"
         L"    </settings>\n"
         L"\n"
         L"    <settings pass=\"specialize\">\n"
         L"        <component name=\"Microsoft-Windows-Shell-Setup\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <ComputerName>%s</ComputerName>\n"
         L"        </component>\n"
         L"        <component name=\"Microsoft-Windows-Deployment\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <RunSynchronous>\n"
@@ -294,7 +352,6 @@ static BOOL generate_autounattend(const wchar_t *output_path,
         L"                    <Order>1</Order>\n"
         L"                    <Path>reg add HKLM\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\OOBE /v BypassNRO /t REG_DWORD /d 1 /f</Path>\n"
         L"                </RunSynchronousCommand>\n",
-        lang, lang_to_input_locale(lang), lang, lang, lang,
         comp_name);
 
     {
@@ -336,7 +393,7 @@ static BOOL generate_autounattend(const wchar_t *output_path,
     if (is_template) {
         fwprintf(f,
             L"        <component name=\"Microsoft-Windows-SecureStartup-FilterDriver\"\n"
-            L"                   processorArchitecture=\"amd64\"\n"
+            L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
             L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
             L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
             L"            <PreventDeviceEncryption>true</PreventDeviceEncryption>\n"
@@ -353,7 +410,7 @@ static BOOL generate_autounattend(const wchar_t *output_path,
         fwprintf(f,
             L"    <settings pass=\"oobeSystem\">\n"
             L"        <component name=\"Microsoft-Windows-Deployment\"\n"
-            L"                   processorArchitecture=\"amd64\"\n"
+            L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
             L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
             L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
             L"            <Reseal>\n"
@@ -364,7 +421,7 @@ static BOOL generate_autounattend(const wchar_t *output_path,
             L"\n"
             L"    <settings pass=\"auditUser\">\n"
             L"        <component name=\"Microsoft-Windows-Deployment\"\n"
-            L"                   processorArchitecture=\"amd64\"\n"
+            L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
             L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
             L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
             L"            <RunSynchronous>\n"
@@ -382,7 +439,7 @@ static BOOL generate_autounattend(const wchar_t *output_path,
         fwprintf(f,
             L"    <settings pass=\"oobeSystem\">\n"
             L"        <component name=\"Microsoft-Windows-International-Core\"\n"
-            L"                   processorArchitecture=\"amd64\"\n"
+            L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
             L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
             L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
             L"            <InputLocale>%s</InputLocale>\n"
@@ -391,7 +448,7 @@ static BOOL generate_autounattend(const wchar_t *output_path,
             L"            <UserLocale>%s</UserLocale>\n"
             L"        </component>\n"
             L"        <component name=\"Microsoft-Windows-Shell-Setup\"\n"
-            L"                   processorArchitecture=\"amd64\"\n"
+            L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
             L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
             L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
             L"            <OOBE>\n"
@@ -730,9 +787,9 @@ HRESULT iso_create_resources(const wchar_t *iso_path,
             if (ssh_enabled) {
                 fputs(
                     "REM Install OpenSSH Server\r\n"
-                    "if exist \"%ISODRV%\\OpenSSH-Win64-v10.0.0.0.msi\" (\r\n"
+                    "if exist \"%ISODRV%\\" SSH_MSI_NAME_A "\" (\r\n"
                     "    echo [SSH] Installing OpenSSH Server... >> \"%LOG%\"\r\n"
-                    "    msiexec /i \"%ISODRV%\\OpenSSH-Win64-v10.0.0.0.msi\" /qn /norestart >> \"%LOG%\" 2>&1\r\n"
+                    "    msiexec /i \"%ISODRV%\\" SSH_MSI_NAME_A "\" /qn /norestart >> \"%LOG%\" 2>&1\r\n"
                     "    echo [SSH] msiexec exit code: %errorlevel% >> \"%LOG%\"\r\n"
                     "    sc config sshd start= auto >> \"%LOG%\" 2>&1\r\n"
                     "    net start sshd >> \"%LOG%\" 2>&1\r\n"
@@ -791,13 +848,13 @@ static BOOL generate_unattend_instance(const wchar_t *output_path,
         L"\n"
         L"    <settings pass=\"specialize\">\n"
         L"        <component name=\"Microsoft-Windows-Shell-Setup\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <ComputerName>%s</ComputerName>\n"
         L"        </component>\n"
         L"        <component name=\"Microsoft-Windows-Deployment\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <RunSynchronous>\n"
@@ -821,13 +878,37 @@ static BOOL generate_unattend_instance(const wchar_t *output_path,
         L"                    <Order>5</Order>\n"
         L"                    <Path>cmd /c for %%d in (D E F G H I J) do @if exist %%d:\\SetupComplete.cmd copy /Y %%d:\\SetupComplete.cmd C:\\Windows\\Setup\\Scripts\\</Path>\n"
         L"                </RunSynchronousCommand>\n"
+#if ASB_IS_ARM64
+        /* ARM only: Windows 11 LabConfig hardware-check bypass keys (no vTPM on
+           ARM). Orders 6-10 continue this component's RunSynchronous. */
+        L"                <RunSynchronousCommand wcm:action=\"add\">\n"
+        L"                    <Order>6</Order>\n"
+        L"                    <Path>reg add HKLM\\SYSTEM\\Setup\\LabConfig /v BypassTPMCheck /t REG_DWORD /d 1 /f</Path>\n"
+        L"                </RunSynchronousCommand>\n"
+        L"                <RunSynchronousCommand wcm:action=\"add\">\n"
+        L"                    <Order>7</Order>\n"
+        L"                    <Path>reg add HKLM\\SYSTEM\\Setup\\LabConfig /v BypassSecureBootCheck /t REG_DWORD /d 1 /f</Path>\n"
+        L"                </RunSynchronousCommand>\n"
+        L"                <RunSynchronousCommand wcm:action=\"add\">\n"
+        L"                    <Order>8</Order>\n"
+        L"                    <Path>reg add HKLM\\SYSTEM\\Setup\\LabConfig /v BypassRAMCheck /t REG_DWORD /d 1 /f</Path>\n"
+        L"                </RunSynchronousCommand>\n"
+        L"                <RunSynchronousCommand wcm:action=\"add\">\n"
+        L"                    <Order>9</Order>\n"
+        L"                    <Path>reg add HKLM\\SYSTEM\\Setup\\LabConfig /v BypassStorageCheck /t REG_DWORD /d 1 /f</Path>\n"
+        L"                </RunSynchronousCommand>\n"
+        L"                <RunSynchronousCommand wcm:action=\"add\">\n"
+        L"                    <Order>10</Order>\n"
+        L"                    <Path>reg add HKLM\\SYSTEM\\Setup\\LabConfig /v BypassCPUCheck /t REG_DWORD /d 1 /f</Path>\n"
+        L"                </RunSynchronousCommand>\n"
+#endif
         L"            </RunSynchronous>\n"
         L"        </component>\n"
         L"    </settings>\n"
         L"\n"
         L"    <settings pass=\"oobeSystem\">\n"
         L"        <component name=\"Microsoft-Windows-International-Core\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <InputLocale>%s</InputLocale>\n"
@@ -836,7 +917,7 @@ static BOOL generate_unattend_instance(const wchar_t *output_path,
         L"            <UserLocale>%s</UserLocale>\n"
         L"        </component>\n"
         L"        <component name=\"Microsoft-Windows-Shell-Setup\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <OOBE>\n"
@@ -1204,9 +1285,9 @@ static void stage_agent_and_setup(const wchar_t *staging, const wchar_t *res_dir
             if (ssh_enabled) {
                 fputs(
                     "REM Install OpenSSH Server\r\n"
-                    "if exist \"%ISODRV%\\OpenSSH-Win64-v10.0.0.0.msi\" (\r\n"
+                    "if exist \"%ISODRV%\\" SSH_MSI_NAME_A "\" (\r\n"
                     "    echo [SSH] Installing OpenSSH Server... >> \"%LOG%\"\r\n"
-                    "    msiexec /i \"%ISODRV%\\OpenSSH-Win64-v10.0.0.0.msi\" /qn /norestart >> \"%LOG%\" 2>&1\r\n"
+                    "    msiexec /i \"%ISODRV%\\" SSH_MSI_NAME_A "\" /qn /norestart >> \"%LOG%\" 2>&1\r\n"
                     "    echo [SSH] msiexec exit code: %errorlevel% >> \"%LOG%\"\r\n"
                     "    sc config sshd start= auto >> \"%LOG%\" 2>&1\r\n"
                     "    net start sshd >> \"%LOG%\" 2>&1\r\n"
@@ -1329,13 +1410,13 @@ BOOL generate_unattend_vhdx(const wchar_t *output_path,
         L"\n"
         L"    <settings pass=\"specialize\">\n"
         L"        <component name=\"Microsoft-Windows-Shell-Setup\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <ComputerName>%s</ComputerName>\n"
         L"        </component>\n"
         L"        <component name=\"Microsoft-Windows-Deployment\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <RunSynchronous>\n"
@@ -1364,6 +1445,10 @@ BOOL generate_unattend_vhdx(const wchar_t *output_path,
                 L"                    <Path>bcdedit /set testsigning on</Path>\n"
                 L"                </RunSynchronousCommand>\n", order++);
         }
+#if ASB_IS_ARM64
+        /* ARM only: Windows 11 LabConfig hardware-check bypass keys (no vTPM on ARM). */
+        write_tpm_bypass_commands(f, order);
+#endif
     }
 
     fwprintf(f,
@@ -1376,7 +1461,7 @@ BOOL generate_unattend_vhdx(const wchar_t *output_path,
     fwprintf(f,
         L"    <settings pass=\"oobeSystem\">\n"
         L"        <component name=\"Microsoft-Windows-International-Core\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <InputLocale>%s</InputLocale>\n"
@@ -1385,7 +1470,7 @@ BOOL generate_unattend_vhdx(const wchar_t *output_path,
         L"            <UserLocale>%s</UserLocale>\n"
         L"        </component>\n"
         L"        <component name=\"Microsoft-Windows-Shell-Setup\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <OOBE>\n"
@@ -1455,13 +1540,13 @@ BOOL generate_unattend_vhdx_template(const wchar_t *output_path,
         L"\n"
         L"    <settings pass=\"specialize\">\n"
         L"        <component name=\"Microsoft-Windows-Shell-Setup\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <ComputerName>%s</ComputerName>\n"
         L"        </component>\n"
         L"        <component name=\"Microsoft-Windows-Deployment\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <RunSynchronous>\n"
@@ -1490,13 +1575,17 @@ BOOL generate_unattend_vhdx_template(const wchar_t *output_path,
                 L"                    <Path>bcdedit /set testsigning on</Path>\n"
                 L"                </RunSynchronousCommand>\n", order++);
         }
+#if ASB_IS_ARM64
+        /* ARM only: Windows 11 LabConfig hardware-check bypass keys (no vTPM on ARM). */
+        write_tpm_bypass_commands(f, order);
+#endif
     }
 
     fwprintf(f,
         L"            </RunSynchronous>\n"
         L"        </component>\n"
         L"        <component name=\"Microsoft-Windows-SecureStartup-FilterDriver\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <PreventDeviceEncryption>true</PreventDeviceEncryption>\n"
@@ -1509,7 +1598,7 @@ BOOL generate_unattend_vhdx_template(const wchar_t *output_path,
     fwprintf(f,
         L"    <settings pass=\"oobeSystem\">\n"
         L"        <component name=\"Microsoft-Windows-Deployment\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <Reseal>\n"
@@ -1520,7 +1609,7 @@ BOOL generate_unattend_vhdx_template(const wchar_t *output_path,
         L"\n"
         L"    <settings pass=\"auditUser\">\n"
         L"        <component name=\"Microsoft-Windows-Deployment\"\n"
-        L"                   processorArchitecture=\"amd64\"\n"
+        L"                   processorArchitecture=\"" ASB_UA_ARCH L"\"\n"
         L"                   publicKeyToken=\"31bf3856ad364e35\"\n"
         L"                   language=\"neutral\" versionScope=\"nonSxS\">\n"
         L"            <RunSynchronous>\n"
@@ -1604,9 +1693,9 @@ BOOL generate_vhdx_setupcomplete(const wchar_t *output_path, BOOL ssh_enabled)
         fputs(
             "REM Install OpenSSH Server\r\n"
             "set SSHDIR=%SystemRoot%\\AppSandbox\r\n"
-            "if exist \"%SSHDIR%\\OpenSSH-Win64-v10.0.0.0.msi\" (\r\n"
+            "if exist \"%SSHDIR%\\" SSH_MSI_NAME_A "\" (\r\n"
             "    echo [SSH] Installing OpenSSH Server... >> \"%LOG%\"\r\n"
-            "    msiexec /i \"%SSHDIR%\\OpenSSH-Win64-v10.0.0.0.msi\" /qn /norestart >> \"%LOG%\" 2>&1\r\n"
+            "    msiexec /i \"%SSHDIR%\\" SSH_MSI_NAME_A "\" /qn /norestart >> \"%LOG%\" 2>&1\r\n"
             "    echo [SSH] msiexec exit code: %errorlevel% >> \"%LOG%\"\r\n"
             "    sc config sshd start= auto >> \"%LOG%\" 2>&1\r\n"
             "    net start sshd >> \"%LOG%\" 2>&1\r\n"
diff --git a/src/backend_win/disk_util.h b/src/backend_win/disk_util.h
index a890d9d..2414534 100644
--- a/src/backend_win/disk_util.h
+++ b/src/backend_win/disk_util.h
@@ -3,6 +3,19 @@
 
 #include <windows.h>
 
+/* Target architecture, resolved at compile time. The supported pairing is
+   x64 build -> x64 host -> x64 guest, and ARM64 build -> ARM host -> ARM guest
+   (no cross-arch installs), so build arch == host arch == guest arch and a
+   single compile-time flag drives every architecture decision: the HCS
+   SecuritySettings (ARM Windows HCS has no vTPM / guest-state isolation), the
+   autounattend processorArchitecture token + Win11 TPM-check bypass, the
+   OpenSSH MSI variant, and the GPU-PV D3D mapping-layer package. */
+#if defined(_M_ARM64)
+#  define ASB_IS_ARM64 1
+#else
+#  define ASB_IS_ARM64 0
+#endif
+
 /* Create a new dynamically-expanding VHDX file.
    size_gb: maximum virtual size in gigabytes. */
 HRESULT vhdx_create(const wchar_t *path, ULONGLONG size_gb);
diff --git a/src/backend_win/gpu_enum.h b/src/backend_win/gpu_enum.h
index e64fa01..abce334 100644
--- a/src/backend_win/gpu_enum.h
+++ b/src/backend_win/gpu_enum.h
@@ -61,7 +61,7 @@ BOOL gpu_append_lxsslib_share(GpuDriverShareList *list);
 
 /* Append a synthetic Plan9 share (name "AppSandbox.GlLayers") exposing the
    host directory that holds the D3D mapping layers (OpenGLOn12/dxil/OpenCLOn12/
-   clon12compiler/vulkan_dzn + dzn_icd.x64.json) and the OpenGL ICD shim. The
+   clon12compiler/vulkan_dzn + dzn_icd.json) and the OpenGL ICD shim. The
    Windows guest agent copies this share AFTER the GPU driver shares and then
    provisions it (stages dxil to System32, sets AppInit_DLLs + the Khronos
    OpenCL/Vulkan ICD registry keys). guest_path is C:\Windows\AppSandbox\d3dlayers.
diff --git a/src/backend_win/hcs_vm.c b/src/backend_win/hcs_vm.c
index 2403147..ae10de8 100644
--- a/src/backend_win/hcs_vm.c
+++ b/src/backend_win/hcs_vm.c
@@ -1,6 +1,7 @@
 #include "hcs_vm.h"
 #include "vm_agent.h"
 #include "ui.h"
+#include "disk_util.h"   /* ASB_IS_ARM64 */
 #include <stdio.h>
 #include <sddl.h>
 #include <aclapi.h>
@@ -1041,9 +1042,14 @@ BOOL hcs_build_vm_json(const VmConfig *config, const wchar_t *endpoint_guid,
             name_esc);
     }
 
-    /* SecuritySettings with TPM — enabled for all Windows VMs.
-       TPM does not block test-signed drivers; only Secure Boot does. */
+    /* SecuritySettings (virtual TPM + GuestStateOnly isolation) — x64 only.
+       The vTPM is required by the Windows 11 guest on x64. ARM Windows HCS
+       supports neither a vTPM nor guest-state isolation, so the whole block is
+       emitted only on x64. The Windows 11 Setup TPM/SecureBoot requirement
+       check is bypassed via the autounattend LabConfig keys (see
+       generate_autounattend in disk_util.c). */
     security_section[0] = L'\0';
+#if !ASB_IS_ARM64
     if (is_windows) {
         wcscpy_s(security_section, 512,
             L",\"SecuritySettings\":{"
@@ -1051,6 +1057,7 @@ BOOL hcs_build_vm_json(const VmConfig *config, const wchar_t *endpoint_guid,
             L"\"Isolation\":{\"IsolationType\":\"GuestStateOnly\"}"
             L"}");
     }
+#endif
 
     /* Plan9 shares — GPU driver directories for agent p9copy.
        Skip for template VMs (no GPU assigned during template creation). */
diff --git a/tools/agent/agent.c b/tools/agent/agent.c
index 372e5fd..24c454b 100644
--- a/tools/agent/agent.c
+++ b/tools/agent/agent.c
@@ -454,7 +454,7 @@ static void gl_provision(const wchar_t *dir)
        The manifest's library_path is the absolute guest DLL path (set host-side
        in d3dlayers.c) so the loader can LoadLibraryEx it under
        LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR, which requires a fully-qualified path. */
-    swprintf_s(path, MAX_PATH, L"%s\\dzn_icd.x64.json", dir);
+    swprintf_s(path, MAX_PATH, L"%s\\dzn_icd.json", dir);
     if (GetFileAttributesW(path) != INVALID_FILE_ATTRIBUTES) {
         if (RegCreateKeyExW(HKEY_LOCAL_MACHINE, L"SOFTWARE\\Khronos\\Vulkan\\Drivers",
                 0, NULL, 0, KEY_SET_VALUE, NULL, &key, NULL) == ERROR_SUCCESS) {
diff --git a/tools/sign/AppSandboxPackage.vcxproj b/tools/sign/AppSandboxPackage.vcxproj
index 65c1737..b27a463 100644
--- a/tools/sign/AppSandboxPackage.vcxproj
+++ b/tools/sign/AppSandboxPackage.vcxproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!--
   AppSandboxPackage — a Utility project that runs tools\sign\make-release.ps1 -NoBuild
-  AFTER the solution builds, but ONLY for Release|x64.
+  -Platform $(Platform) AFTER the solution builds, for Release|x64 or Release|ARM64.
 
   In AppSandbox.sln this project is set to depend on every other project, so Visual
   Studio builds it LAST and SKIPS it entirely if any project failed to build — i.e.
@@ -54,9 +54,9 @@
     <DisableFastUpToDateCheck>true</DisableFastUpToDateCheck>
   </PropertyGroup>
   <Target Name="AppSandboxSignAndPackage" AfterTargets="Build"
-          Condition="'$(Configuration)|$(Platform)'=='Release|x64' And '$(ASB_SKIP_PACKAGE_PROJECT)' != '1'">
-    <Message Importance="high" Text="==== AppSandbox: make-release.ps1 -NoBuild (sign + package) ====" />
-    <Exec Command="powershell.exe -NoProfile -ExecutionPolicy Bypass -File &quot;$(SolutionDir)tools\sign\make-release.ps1&quot; -NoBuild" />
+          Condition="'$(Configuration)'=='Release' And ('$(Platform)'=='x64' Or '$(Platform)'=='ARM64') And '$(ASB_SKIP_PACKAGE_PROJECT)' != '1'">
+    <Message Importance="high" Text="==== AppSandbox: make-release.ps1 -NoBuild -Platform $(Platform) (sign + package) ====" />
+    <Exec Command="powershell.exe -NoProfile -ExecutionPolicy Bypass -File &quot;$(SolutionDir)tools\sign\make-release.ps1&quot; -NoBuild -Platform $(Platform)" />
   </Target>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
 </Project>
diff --git a/tools/sign/SIGNING.md b/tools/sign/SIGNING.md
index 71fd988..5e1bb11 100644
--- a/tools/sign/SIGNING.md
+++ b/tools/sign/SIGNING.md
@@ -36,6 +36,8 @@ via attestation through Partner Center.
    associated** to it (Partner Center adds the cert under the hardware account).
 3. **Azure AD (Entra) app** for the Hardware submission API (below).
 4. Windows SDK + WDK installed (`signtool.exe`, `infverif.exe`, `makecab.exe`).
+5. For **ARM64** releases: the **ARM64 MSVC + WDK build tools** (cross-building from an x64
+   host is fully supported — no ARM device is needed to build, sign, or submit).
 
 ### 2a. Create the Entra app (for the submission API)
 
@@ -77,11 +79,11 @@ tools\sign\test-hardware-api.ps1
 | File | Committed? | Purpose |
 | --- | --- | --- |
 | `partner-center.local.json` | **no** (git-ignored) | Entra API creds (tenant/client/secret) |
-| `submission-config.json` | yes | Product names, OS signature targets, driver→cab mapping, timestamp URL, optional `evCertThumbprint` |
+| `submission-config.json` | yes | Product names, OS signature targets, driver→cab mapping, timestamp URL, optional `evCertThumbprint` (x64 values; `sign-drivers.ps1 -Platform ARM64` derives the ARM64 equivalents at sign time) |
 | `test-hardware-api.ps1` | yes | Validate creds + Hardware roles |
 | `sign-drivers.ps1` | yes | EV-sign drivers (binary + catalog + cab) → attestation submit (both in parallel) → download MS-signed |
 | `make-release.ps1` | yes | Build → (if YubiKey) sign all binaries + driver-attest + ZIP; else skip |
-| `AppSandboxPackage.vcxproj` | yes | Utility project; runs `make-release.ps1 -NoBuild` after a successful `Release|x64` VS build |
+| `AppSandboxPackage.vcxproj` | yes | Utility project; runs `make-release.ps1 -NoBuild -Platform $(Platform)` after a successful `Release|x64` **or** `Release|ARM64` VS build |
 | `SIGNING.md` | yes | This document |
 
 Versioning lives at the **repo root**: `Directory.Build.props` (the version numbers + the
@@ -97,18 +99,20 @@ that is inherent to EV signing — so the goal is "keep it out of source," not s
 ## 4. Running it
 
 ### From Visual Studio (the usual path)
-**Build Solution** in **Release|x64**. The `AppSandboxPackage` project depends on every
-other project, so Visual Studio builds it **last** and — via its `AfterTargets="Build"`
-step — runs `make-release.ps1 -NoBuild`, **but only if every project built successfully**
-(a failed build skips it, so no signing/packaging on a broken build). With no EV YubiKey
-it no-ops (build only); with the token in it signs + attestation-signs + zips. Debug
-builds and Release|ARM64 never trigger it.
+**Build Solution** in **Release|x64** or **Release|ARM64**. The `AppSandboxPackage` project
+depends on every other project, so Visual Studio builds it **last** and — via its
+`AfterTargets="Build"` step — runs `make-release.ps1 -NoBuild -Platform $(Platform)`, **but
+only if every project built successfully** (a failed build skips it, so no signing/packaging
+on a broken build). With no EV YubiKey it no-ops (build only); with the token in it signs +
+attestation-signs + zips (ARM64 outputs to `bin\Release-ARM64`, with its ARM64 attestation
+profile and `-win-arm64.zip`). Debug builds never trigger it.
 
 ### Normal release (the one command)
 ```powershell
-tools\sign\make-release.ps1
+tools\sign\make-release.ps1                  # x64
+tools\sign\make-release.ps1 -Platform ARM64  # Windows on ARM
 ```
-- Builds `Release|x64`.
+- Builds `Release|x64` (or `Release|ARM64` with `-Platform ARM64`; output under `bin\Release-ARM64\`).
 - **If the EV YubiKey is in:** EV-signs all binaries — app `.exe`/`.dll` **and** driver
   `.sys`/`.dll` — in one call (**PIN 1**); then `sign-drivers.ps1` regenerates + EV-signs the
   catalogs (**PIN 2**) and EV-signs the cabs (**PIN 3**), submits both drivers to Microsoft,
@@ -164,16 +168,34 @@ API flow (`https://manage.devcenter.microsoft.com/v2.0/my/hardware`): token →
 URL) → PUT the signed CAB → `POST …/commit` → poll `workflowStatus.state` until `completed` →
 download `downloads.items[type=="signedPackage"]`. Both drivers run **in parallel**.
 
-**One product per version.** A product accepts exactly **one** submission (a second returns
-`"Initial submission already exists"`), so each release is its own product — the version is
-baked into the product name (e.g. `App Sandbox Virtual Display Driver 0.1.0`) so the dashboard
-reads as a version history. Products **cannot be deleted** via the API (only renamed, via
+**One product per version per architecture.** A product accepts exactly **one** submission (a
+second returns `"Initial submission already exists"`), so each release is its own product — the
+version **and architecture** are baked into the product name (e.g. `App Sandbox Virtual Display
+Driver x64 0.1.0` / `… ARM64 0.1.0`) so the dashboard reads as a per-arch version history.
+Products **cannot be deleted** via the API (only renamed, via
 `PATCH /products/{id}`), so retire old ones by renaming, not removal.
 
-**OS targets** are set in `submission-config.json` → `requestedSignatures`. Current
-codes are listed in Microsoft's *Get product data* doc; Windows 11 x64:
-`WINDOWS_v100_X64_CO_FULL` (21H2), `_NI_FULL` (22H2), `_GE_FULL` (24H2),
-`_25H2_FULL` (25H2).
+**OS targets** are set in `submission-config.json` → `requestedSignatures`. Current codes
+are listed in Microsoft's *Get product data* doc; Windows 11 x64: `WINDOWS_v100_X64_CO_FULL`
+(21H2), `_NI_FULL` (22H2), `_GE_FULL` (24H2), `_25H2_FULL` (25H2). For an ARM64 build,
+`sign-drivers.ps1 -Platform ARM64` rewrites these to the `ARM64` codes (and uses `inf2cat
+/os:10_CO_ARM64`) at sign time, so the committed config stays x64.
+
+**x64 and ARM64 are submitted separately.** `sign-drivers.ps1 -Platform <arch>` (driven by
+`make-release.ps1 -Platform <arch>`) builds the cab from that arch's driver output,
+regenerates the catalog with `inf2cat /os:10_CO_<ARCH>`, and creates its **own** product.
+The **architecture is in the product/submission name** (`… x64 <ver>` / `… ARM64 <ver>`)
+so the two are easy to tell apart in the Partner Center dashboard. (A single combined
+multi-arch submission is technically possible but would need both arches built before
+signing, which breaks the per-platform "build one config → auto sign+zip" automation —
+hence separate per-arch submissions.)
+
+**ARM64 ApiValidator** (the Universal-DDI check the WDK forces on ARM64 drivers) is **disabled
+for ARM64 cross-builds from a non-ARM64 host** (`ApiValidator_Enable=false` in
+`Directory.Build.props`, gated on `Platform==ARM64` + host≠ARM64). The WDK defaults it to the x86
+ApiExtractor, which can't read an ARM64 PE and fails with exit 193; native ARM64 hosts and all x64
+builds still run it, and Microsoft re-runs API validation on submission. Same rationale as the
+InfVerif skip below.
 
 **INF verification** (`infverif /h`, required by Partner Center since Apr 2025) runs at
 **build time inside Visual Studio**. Command-line / CI builds skip the build-time task
diff --git a/tools/sign/make-release.ps1 b/tools/sign/make-release.ps1
index f6e05e7..ba931a0 100644
--- a/tools/sign/make-release.ps1
+++ b/tools/sign/make-release.ps1
@@ -2,7 +2,7 @@
   make-release.ps1 - Build AppSandbox, then conditionally sign + package.
 
   Flow:
-    1. Build the solution (Release|x64) unless -NoBuild.
+    1. Build the solution (Release|$Platform) unless -NoBuild.
     2. Check whether the App Sandbox LLC EV YubiKey is plugged in.
          - NOT present  -> SKIP signing, driver attestation, and ZIP.
                            The (test-signed) dev build is left as-is. Done.
@@ -14,15 +14,21 @@
   So nothing is signed or zipped on an ordinary dev machine without the token.
 
   USAGE:
-    .\make-release.ps1                  # build + (if YubiKey) sign + attest + zip
-    .\make-release.ps1 -NoBuild         # package the current bin\Release
+    .\make-release.ps1                  # x64: build + (if YubiKey) sign + attest + zip
+    .\make-release.ps1 -Platform ARM64  # Windows on ARM (bin\Release-ARM64 -> *-win-arm64.zip)
+    .\make-release.ps1 -NoBuild         # package the current bin\Release[-ARM64]
     .\make-release.ps1 -SkipDrivers     # sign app binaries + zip; leave drivers as-is
     .\make-release.ps1 -ForceDriverSign # re-submit drivers for attestation even if cached
+
+  -Platform selects the bin\ output dir (ARM64 -> bin\Release-ARM64), the driver
+  attestation OS/signature codes (sign-drivers.ps1 -Platform rewrites the x64 config
+  at sign time), and the zip name. The AppSandboxPackage project passes
+  -Platform $(Platform) after a Release build.
 #>
 [CmdletBinding()]
 param(
   [string]$Configuration = 'Release',
-  [string]$Platform      = 'x64',
+  [ValidateSet('x64','ARM64')][string]$Platform = 'x64',
   [string]$OS            = 'win',   # OS token in the zip name; not passed to MSBuild
   [string]$Version       = '',     # empty => read from Directory.Build.props (single source)
   [switch]$NoBuild,
@@ -40,7 +46,10 @@ $env:ASB_SKIP_PACKAGE_PROJECT = '1'
 
 $repo = (Resolve-Path (Join-Path $PSScriptRoot '..\..')).Path
 $sln  = Join-Path $repo 'AppSandbox.sln'
-$bin  = Join-Path $repo ("bin\{0}" -f $Configuration)   # x64 -> bin\Release
+# Output dir matches the .vcxproj OutDir convention: x64 -> bin\Release,
+# ARM64 -> bin\Release-ARM64.
+$binLeaf = if ($Platform -eq 'ARM64') { "$Configuration-ARM64" } else { $Configuration }
+$bin  = Join-Path $repo ("bin\{0}" -f $binLeaf)
 
 $cfgPath = Join-Path $PSScriptRoot 'submission-config.json'
 $cfg     = if (Test-Path $cfgPath) { Get-Content $cfgPath -Raw | ConvertFrom-Json } else { $null }
@@ -84,6 +93,11 @@ function Get-AsbVersion([string]$repoRoot) {
 #                         returns an error (never UI) when the specific card bearing it is absent.
 #                         This is what tells our token apart from some unrelated card the user inserted.
 if (-not ([System.Management.Automation.PSTypeName]'AsbScReader').Type) {
+    # Add-Type shells out to the .NET Framework C# compiler, which reads the LIB environment
+    # variable and fails the compile (CS1668, warning-as-error) on any entry that does not exist.
+    # The VS ARM64 build pushes a non-existent ...\atlmfc\lib\ARM64 onto LIB (the ATL/MFC ARM64
+    # libs aren't installed); csc needs nothing from LIB here, so drop missing entries first.
+    if ($env:LIB) { $env:LIB = (($env:LIB -split ';') | Where-Object { $_ -and (Test-Path $_) }) -join ';' }
     Add-Type -TypeDefinition @'
 using System;
 using System.Collections.Generic;
@@ -290,8 +304,8 @@ if (-not $SkipDrivers) {
         if ($reusable) {
             Write-Host "Reusing existing Microsoft-signed drivers (v$($asb.Full)) from drivers-signed - no resubmit."
         } else {
-            Write-Host "Driver attestation signing (sign-drivers.ps1) - Microsoft round-trip..."
-            & (Join-Path $PSScriptRoot 'sign-drivers.ps1')
+            Write-Host "Driver attestation signing (sign-drivers.ps1 -Platform $Platform) - Microsoft round-trip..."
+            & (Join-Path $PSScriptRoot 'sign-drivers.ps1') -Platform $Platform
             if ($LASTEXITCODE -ne 0) { throw "Driver attestation failed." }
         }
         # Deposit the MS-signed drivers into bin\Release\drivers (deposited .sys/.dll match the MS
@@ -360,7 +374,7 @@ $files | ForEach-Object { Write-Host ("  " + $_.FullName.Substring($stage.Length
 $mb = [math]::Round((($files | Measure-Object Length -Sum).Sum) / 1MB, 1)
 Write-Host ("--- {0} files, {1} MB ---`n" -f $files.Count, $mb)
 
-$zip = Join-Path $bin ("AppSandbox-{0}-{1}-{2}.zip" -f $Version, $OS, $Platform)
+$zip = Join-Path $bin ("AppSandbox-{0}-{1}-{2}.zip" -f $Version, $OS, $Platform.ToLower())
 if (Test-Path $zip) { Remove-Item $zip -Force }
 # Flat layout: the items sit at the zip root (file.zip\AppSandbox.exe, file.zip\drivers\...),
 # with the drivers\ / resources\ / web\ subfolders preserved - no extra parent folder.
diff --git a/tools/sign/sign-drivers.ps1 b/tools/sign/sign-drivers.ps1
index aa862b8..9e643cb 100644
--- a/tools/sign/sign-drivers.ps1
+++ b/tools/sign/sign-drivers.ps1
@@ -38,6 +38,7 @@
 param(
   [string]$ConfigPath   = (Join-Path $PSScriptRoot 'submission-config.json'),
   [string]$CredPath     = (Join-Path $PSScriptRoot 'partner-center.local.json'),
+  [ValidateSet('x64','ARM64')][string]$Platform = 'x64',   # build target arch
   [switch]$NoCab,
   [switch]$NoSign,
   [switch]$SkipSubmit,
@@ -87,6 +88,11 @@ function Invoke-EvSign([string[]]$files, [string]$what) {
 #                         returns an error (never UI) when the specific card bearing it is absent.
 #                         This is what tells our token apart from some unrelated card the user inserted.
 if (-not ([System.Management.Automation.PSTypeName]'AsbScReader').Type) {
+    # Add-Type shells out to the .NET Framework C# compiler, which reads the LIB environment
+    # variable and fails the compile (CS1668, warning-as-error) on any entry that does not exist.
+    # The VS ARM64 build pushes a non-existent ...\atlmfc\lib\ARM64 onto LIB (the ATL/MFC ARM64
+    # libs aren't installed); csc needs nothing from LIB here, so drop missing entries first.
+    if ($env:LIB) { $env:LIB = (($env:LIB -split ';') | Where-Object { $_ -and (Test-Path $_) }) -join ';' }
     Add-Type -TypeDefinition @'
 using System;
 using System.Collections.Generic;
@@ -401,6 +407,18 @@ function New-DriverCab($d, [string]$workDir) {
 
 if (-not (Test-Path $ConfigPath)) { throw "Config not found: $ConfigPath" }
 $cfg            = Get-Content $ConfigPath -Raw | ConvertFrom-Json
+
+# The config holds the x64 defaults. For an ARM64 build target, rewrite the
+# arch-specific values (output dirs, inf2cat OS, requested signatures); on x64
+# the config is used as-is.
+if ($Platform -eq 'ARM64') {
+    $cfg.workDir   = $cfg.workDir   -replace 'bin\\Release(?=\\)', 'bin\Release-ARM64'
+    $cfg.outDir    = $cfg.outDir    -replace 'bin\\Release(?=\\)', 'bin\Release-ARM64'
+    $cfg.symbolDir = $cfg.symbolDir -replace '\\x64\\', '\ARM64\'
+    $cfg.inf2catOs = $cfg.inf2catOs -replace 'X64', 'ARM64'
+    $cfg.requestedSignatures = @($cfg.requestedSignatures | ForEach-Object { $_ -replace 'X64','ARM64' })
+    foreach ($d in $cfg.drivers) { $d.sourceDir = $d.sourceDir -replace 'bin\\Release(?=\\)', 'bin\Release-ARM64' }
+}
 $asb            = Get-AsbVersion          # version from Directory.Build.props (single source)
 $workDir          = Resolve-RelPath $cfg.workDir
 $script:OutDir    = Resolve-RelPath $cfg.outDir
@@ -483,7 +501,8 @@ $ver = $asb.Short
 $pending = @()
 foreach ($j in $jobs) {
     $d = $j.Driver
-    $productDisplayName = "$($d.productName) $ver"
+    $archTag = if ($Platform -eq 'ARM64') { ' ARM64' } else { '' }
+    $productDisplayName = "$($d.productName)$archTag $ver"
     Write-Host "`n=== $productDisplayName ==="
 
     $product = Invoke-Api POST "$ApiBase/products" @{
diff --git a/tools/vdd/Package/Package.vcxproj b/tools/vdd/Package/Package.vcxproj
index ddcffaf..8a215c3 100644
--- a/tools/vdd/Package/Package.vcxproj
+++ b/tools/vdd/Package/Package.vcxproj
@@ -113,7 +113,8 @@
 copy /Y "$(SolutionDir)ARM64\$(Configuration)\AppSandboxVDD\AppSandboxVDD.dll" "$(SolutionDir)bin\$(Configuration)-ARM64\drivers\"
 copy /Y "$(SolutionDir)ARM64\$(Configuration)\AppSandboxVDD\AppSandboxVDD.inf" "$(SolutionDir)bin\$(Configuration)-ARM64\drivers\"
 copy /Y "$(SolutionDir)ARM64\$(Configuration)\AppSandboxVDD\appsandboxvdd.cat" "$(SolutionDir)bin\$(Configuration)-ARM64\drivers\AppSandboxVDD.cat"
-powershell -NoProfile -Command "$sig = Get-AuthenticodeSignature '$(SolutionDir)ARM64\$(Configuration)\AppSandboxVDD\appsandboxvdd.cat'; if ($sig.SignerCertificate) { [IO.File]::WriteAllBytes('$(SolutionDir)bin\$(Configuration)-ARM64\drivers\AppSandboxVDD.cer', $sig.SignerCertificate.RawData) }"</Command>
+powershell -NoProfile -Command "$sig = Get-AuthenticodeSignature '$(SolutionDir)ARM64\$(Configuration)\AppSandboxVDD\appsandboxvdd.cat'; if ($sig.SignerCertificate) { [IO.File]::WriteAllBytes('$(SolutionDir)bin\$(Configuration)-ARM64\drivers\AppSandboxVDD.cer', $sig.SignerCertificate.RawData) }"
+copy /Y "$(SolutionDir)vendor\devcon\arm64\devcon.exe" "$(SolutionDir)bin\$(Configuration)-ARM64\drivers\"</Command>
       <Message>Copying VDD driver files to bin\$(Configuration)-ARM64\drivers\...</Message>
     </PostBuildEvent>
   </ItemDefinitionGroup>
@@ -134,7 +135,8 @@ copy /Y "$(SolutionDir)vendor\devcon\devcon.exe" "$(SolutionDir)bin\$(Configurat
 copy /Y "$(SolutionDir)ARM64\$(Configuration)\AppSandboxVDD\AppSandboxVDD.dll" "$(SolutionDir)bin\$(Configuration)-ARM64\drivers\"
 copy /Y "$(SolutionDir)ARM64\$(Configuration)\AppSandboxVDD\AppSandboxVDD.inf" "$(SolutionDir)bin\$(Configuration)-ARM64\drivers\"
 copy /Y "$(SolutionDir)ARM64\$(Configuration)\AppSandboxVDD\appsandboxvdd.cat" "$(SolutionDir)bin\$(Configuration)-ARM64\drivers\AppSandboxVDD.cat"
-powershell -NoProfile -Command "$sig = Get-AuthenticodeSignature '$(SolutionDir)ARM64\$(Configuration)\AppSandboxVDD\appsandboxvdd.cat'; if ($sig.SignerCertificate) { [IO.File]::WriteAllBytes('$(SolutionDir)bin\$(Configuration)-ARM64\drivers\AppSandboxVDD.cer', $sig.SignerCertificate.RawData) }"</Command>
+powershell -NoProfile -Command "$sig = Get-AuthenticodeSignature '$(SolutionDir)ARM64\$(Configuration)\AppSandboxVDD\appsandboxvdd.cat'; if ($sig.SignerCertificate) { [IO.File]::WriteAllBytes('$(SolutionDir)bin\$(Configuration)-ARM64\drivers\AppSandboxVDD.cer', $sig.SignerCertificate.RawData) }"
+copy /Y "$(SolutionDir)vendor\devcon\arm64\devcon.exe" "$(SolutionDir)bin\$(Configuration)-ARM64\drivers\"</Command>
       <Message>Copying VDD driver files to bin\$(Configuration)-ARM64\drivers\...</Message>
     </PostBuildEvent>
   </ItemDefinitionGroup>
diff --git a/vendor/devcon/arm64/devcon.exe b/vendor/devcon/arm64/devcon.exe
new file mode 100644
index 0000000..a8be9a5
Binary files /dev/null and b/vendor/devcon/arm64/devcon.exe differ