diff --git a/harness/ruview/.harness/manifest.json b/harness/ruview/.harness/manifest.json
index 590a08714..1350e0f9c 100644
--- a/harness/ruview/.harness/manifest.json
+++ b/harness/ruview/.harness/manifest.json
@@ -66,7 +66,7 @@
     "src/policy.js": "baad5eb8c3eb2e416e0a71b342ad850d7c8413d7d976571ebf596937f69da8e2",
     "src/process-runner.js": "49533b038044dfb8bc76ed01c030d06a9856ead0836157fb693e2a7d40f786d6",
     "src/redact.js": "ebf1afff46341078706b0401838c53db043603586e280d51ece5cf1feba35189",
-    "src/remote.js": "68f901411063fd515a52dad41ffd5c599765a53de34a080715232825eaf207b3",
+    "src/remote.js": "ea433cf719729963a50ebede9442136e72f1eff145c0b3c5e837c6c56fa1ccdf",
     "src/repo-trust.js": "06e2a94d7113ed936f208a12b7fcc785801c215a3e2c5e7418f6238d991a289c",
     "src/sdk.d.ts": "d4c80689248c197b2ddb1ebf4cd7d8f2e55716722074d9e1cdb8029b2dfa19f7",
     "src/sdk.js": "1ac29fb389ed86e0f62ecfddbbd31614c58e832a8181495caa83fe5cf8b30bc4",
@@ -75,7 +75,7 @@
     "src/training.js": "bd8a6c12eba4f9d2f8990fa9692cd04c743ea247f9b13e10f8717ceefcbd09ac",
     "src/ui/console-widget.js": "0d2f707d57b5ec54968dee1dc80f31c7db9152dcadfc48700c18379dabb55462"
   },
-  "filesDigest": "f609508982d1fdc67fa7b90e1286e25945f920ba45e8fde95f76234848cf3be9",
+  "filesDigest": "edc6be28115ad21f18954066e989a6b4aaae2137b2f4e6d6571312beef610288",
   "brainDigest": "c0fb7b079ded157059b91601361429944697dae3cc42abc00dfe1a680986b0f4",
   "gateFingerprint": "6e53c784eee38310188948fc75fb49e6b4ebc04e247d01b903fa8c8a92d67bdd",
   "developmentPins": {
diff --git a/harness/ruview/.harness/manifest.sha256 b/harness/ruview/.harness/manifest.sha256
index 6050050c5..054df24f9 100644
--- a/harness/ruview/.harness/manifest.sha256
+++ b/harness/ruview/.harness/manifest.sha256
@@ -1 +1 @@
-4c69daba76af8460fe5101da07aeab58cd84376ca642280e038f52cf3c4676d6  manifest.json
+0517e22827b8acc7d8550e1e560e4f13ca79397977c52c30cf23770dead2327a  manifest.json
diff --git a/harness/ruview/src/remote.js b/harness/ruview/src/remote.js
index db0b7b659..b3c759ef9 100644
--- a/harness/ruview/src/remote.js
+++ b/harness/ruview/src/remote.js
@@ -60,10 +60,14 @@ const OWNER_ONLY_ACL = [
  * inherited ACLs. Replace them with a single full-control grant for the owner.
  * Fails closed: an unrestricted hosts file is an error, not a warning.
  */
-export function restrictToOwner(path, { platform = process.platform, exec = spawnSync } = {}) {
+export function restrictToOwner(path, { platform = process.platform, exec = spawnSync, env = process.env } = {}) {
   if (platform !== 'win32') return 'posix-0600';
+  // pwsh -> node -> powershell.exe otherwise inherits PS7's incompatible
+  // module paths. Let Windows PowerShell construct its own defaults without
+  // changing the caller's environment or execution policy (about_PSModulePath).
+  const childEnv = Object.fromEntries(Object.entries(env).filter(([key]) => key.toUpperCase() !== 'PSMODULEPATH'));
   const r = exec('powershell.exe', ['-NoLogo', '-NoProfile', '-NonInteractive', '-Command', OWNER_ONLY_ACL], {
-    input: JSON.stringify({ path }), encoding: 'utf8', windowsHide: true, timeout: 10_000, maxBuffer: 16_384,
+    input: JSON.stringify({ path }), env: childEnv, encoding: 'utf8', windowsHide: true, timeout: 10_000, maxBuffer: 16_384,
   });
   if (r.error || r.status !== 0) {
     throw new Error(`could not restrict ${path} to the current user (ACL helper exit ${r.status ?? r.error?.code}); the hosts file was not made private`);
diff --git a/harness/ruview/test/remote.test.mjs b/harness/ruview/test/remote.test.mjs
index bfe8f1fb8..5486190c5 100644
--- a/harness/ruview/test/remote.test.mjs
+++ b/harness/ruview/test/remote.test.mjs
@@ -1,6 +1,6 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
-import { existsSync, mkdtempSync, readFileSync, rmSync, statSync } from 'node:fs';
+import { existsSync, mkdirSync, mkdtempSync, readFileSync, rmSync, statSync, writeFileSync } from 'node:fs';
 import { spawnSync } from 'node:child_process';
 import { tmpdir, userInfo } from 'node:os';
 import { dirname, join, resolve } from 'node:path';
@@ -131,15 +131,49 @@ test('Windows hosts-file restriction removes explicit grants and handles literal
   });
 });
 
+test('Windows ACL helper isolates incompatible inherited PowerShell modules', { skip: process.platform !== 'win32' }, async () => {
+  await withHosts(async (path) => {
+    const modules = join(dirname(path), 'modules');
+    const utility = join(modules, 'Microsoft.PowerShell.Utility');
+    mkdirSync(utility, { recursive: true });
+    // Reproduce pwsh7 -> node -> Windows PowerShell5 without installing pwsh:
+    // this higher-priority module advertises the cmdlet but requires PS7.
+    writeFileSync(join(utility, 'Microsoft.PowerShell.Utility.psd1'),
+      "@{ ModuleVersion='7.0.0'; PowerShellVersion='7.0'; CmdletsToExport=@('ConvertFrom-Json') }");
+    const inherited = Object.fromEntries(Object.entries(process.env).filter(([key]) => key.toUpperCase() !== 'PSMODULEPATH'));
+    inherited.PSModulePath = `${modules};${process.env.PSModulePath || ''}`;
+    const original = { ...inherited };
+    const parentPath = process.env.PSModulePath;
+    const control = spawnSync('powershell.exe', ['-NoProfile', '-NonInteractive', '-Command', "'{}' | ConvertFrom-Json"], {
+      env: inherited, encoding: 'utf8', windowsHide: true, timeout: 10_000,
+    });
+    assert.equal(control.status, 1, control.stderr);
+    assert.match(control.stderr, /CouldNotAutoloadMatchingModule/);
+    const saved = saveHost({ name: 'pi', ssh: 'ruv@pi.local' }, path, { env: inherited });
+    assert.equal(saved.access, 'windows-acl-owner-only');
+    assert.ok(Object.keys(inherited).length === Object.keys(original).length
+      && Object.entries(original).every(([key, value]) => inherited[key] === value),
+    'the caller environment is unchanged');
+    assert.equal(process.env.PSModulePath, parentPath, 'the process environment is unchanged');
+    const acl = spawnSync('icacls', [path], { encoding: 'utf8' });
+    assert.equal(acl.status, 0, acl.stderr);
+    const grants = acl.stdout.split('\n').filter(line => /:\(/.test(line));
+    assert.equal(grants.length, 1, acl.stdout);
+  });
+});
+
 test('Windows hosts-file restriction fails closed and keeps input out of PowerShell source', () => {
   const calls = [];
   const path = "C:/x/hosts $(throw 'injected').json";
-  const ok = restrictToOwner(path, { platform: 'win32', exec: (cmd, args, options) => { calls.push({ cmd, args, options }); return { status: 0 }; } });
+  const env = { SystemRoot: 'C:/Windows', pSmOdUlEpAtH: 'incompatible-PS7-modules', KEEP: 'unchanged' };
+  const ok = restrictToOwner(path, { platform: 'win32', env, exec: (cmd, args, options) => { calls.push({ cmd, args, options }); return { status: 0 }; } });
   assert.equal(ok, 'windows-acl-owner-only');
   assert.equal(calls[0].cmd, 'powershell.exe');
   assert.deepEqual(calls[0].args.slice(0, 4), ['-NoLogo', '-NoProfile', '-NonInteractive', '-Command']);
   assert.ok(!calls[0].args.at(-1).includes(path));
   assert.deepEqual(JSON.parse(calls[0].options.input), { path });
+  assert.deepEqual(calls[0].options.env, { SystemRoot: 'C:/Windows', KEEP: 'unchanged' });
+  assert.equal(env.pSmOdUlEpAtH, 'incompatible-PS7-modules');
   for (const result of [{ status: 5 }, { status: null, error: { code: 'ENOENT' } }, { status: null, error: { code: 'ETIMEDOUT' } }]) {
     assert.throws(() => restrictToOwner(path, { platform: 'win32', exec: () => result }), /not made private/);
   }