diff --git a/.changeset/fix-ps-execution-policy.md b/.changeset/fix-ps-execution-policy.md
new file mode 100644
index 000000000..6bd7304e8
--- /dev/null
+++ b/.changeset/fix-ps-execution-policy.md
@@ -0,0 +1,5 @@
+---
+'@bradygaster/squad-cli': patch
+---
+
+Add doctor check for unsigned .ps1 shim on Windows that blocks PowerShell execution. Documents workaround in README.
diff --git a/README.md b/README.md
index c19d85c18..ca3bd5c5a 100644
--- a/README.md
+++ b/README.md
@@ -39,6 +39,18 @@ squad init
 
 **✓ Validate:** Check that `.squad/team.md` was created in your project.
 
+#### Windows (PowerShell)
+
+If you see `PSSecurityException: UnauthorizedAccess` after installing globally,
+PowerShell is blocking the unsigned `.ps1` shim that npm creates. Fix it by
+removing the shim — PowerShell will fall back to the `.cmd` version which works fine:
+
+```powershell
+Remove-Item "$env:APPDATA\npm\squad.ps1"
+```
+
+Or run `squad doctor` to detect this automatically. You can also use `cmd.exe` or invoke via `npx @bradygaster/squad-cli`.
+
 ### 3. Authenticate with GitHub (for Issues, PRs, and Ralph)
 
 ```bash
diff --git a/packages/squad-cli/scripts/remove-ps1-shim.mjs b/packages/squad-cli/scripts/remove-ps1-shim.mjs
new file mode 100644
index 000000000..4024deab6
--- /dev/null
+++ b/packages/squad-cli/scripts/remove-ps1-shim.mjs
@@ -0,0 +1,52 @@
+#!/usr/bin/env node
+/**
+ * remove-ps1-shim.mjs — Remove the unsigned squad.ps1 shim on Windows.
+ *
+ * npm global install creates both squad.cmd and squad.ps1 in the npm prefix.
+ * PowerShell prefers .ps1 over .cmd, but blocks unsigned scripts with the
+ * default execution policy (Restricted / AllSigned). Removing the .ps1 shim
+ * lets PowerShell fall back to squad.cmd, which works fine.
+ *
+ * Usage:
+ *   node node_modules/@bradygaster/squad-cli/scripts/remove-ps1-shim.mjs
+ *
+ * Or just run in PowerShell:
+ *   Remove-Item "$env:APPDATA\npm\squad.ps1"
+ *
+ * See: https://github.com/bradygaster/squad/issues/758
+ */
+
+import { existsSync, unlinkSync } from 'node:fs';
+import { join, isAbsolute } from 'node:path';
+
+if (process.platform !== 'win32') {
+  console.log('ℹ️  Not on Windows — nothing to do.');
+  process.exit(0);
+}
+
+const configuredPrefix = process.env['npm_config_prefix'];
+const appData = process.env['APPDATA'];
+const npmPrefix = configuredPrefix || (appData ? join(appData, 'npm') : undefined);
+
+if (!npmPrefix || !isAbsolute(npmPrefix)) {
+  console.error('❌ Unable to determine absolute npm prefix.');
+  console.error('   npm_config_prefix and APPDATA are not set.');
+  process.exit(1);
+}
+
+const ps1Path = join(npmPrefix, 'squad.ps1');
+
+if (!existsSync(ps1Path)) {
+  console.log(`✅ ${ps1Path} does not exist — no action needed.`);
+  process.exit(0);
+}
+
+try {
+  unlinkSync(ps1Path);
+  console.log(`✅ Removed ${ps1Path}`);
+  console.log('   PowerShell will now use squad.cmd instead.');
+} catch (err) {
+  console.error(`❌ Could not remove ${ps1Path}: ${err.message}`);
+  console.error('   Try running as Administrator, or manually delete the file.');
+  process.exit(1);
+}
diff --git a/packages/squad-cli/src/cli/commands/doctor.ts b/packages/squad-cli/src/cli/commands/doctor.ts
index 1f4a1673b..994793035 100644
--- a/packages/squad-cli/src/cli/commands/doctor.ts
+++ b/packages/squad-cli/src/cli/commands/doctor.ts
@@ -263,6 +263,33 @@ function formatAge(seconds: number): string {
   return `${seconds}s`;
 }
 
+// ── Windows .ps1 shim check (#758) ──────────────────────────────────
+
+/**
+ * Detect the unsigned .ps1 shim that npm creates on global install.
+ * PowerShell's default execution policy blocks unsigned scripts, so
+ * the .ps1 shim prevents `squad` from running in PowerShell on Windows.
+ * The .cmd shim works fine — users just need to remove the .ps1 file.
+ */
+export function checkWindowsPs1Shim(): DoctorCheck | undefined {
+  if (process.platform !== 'win32') return undefined;
+
+  const configuredPrefix = process.env['npm_config_prefix'];
+  const appData = process.env['APPDATA'];
+  const npmPrefix = configuredPrefix || (appData ? path.join(appData, 'npm') : undefined);
+  if (!npmPrefix || !path.isAbsolute(npmPrefix)) return undefined;
+  const ps1Path = path.join(npmPrefix, 'squad.ps1');
+
+  if (!fileExists(ps1Path)) return undefined;
+
+  return {
+    name: 'Windows PowerShell shim',
+    status: 'warn',
+    message: 'squad.ps1 exists and may be blocked by execution policy. ' +
+      'Fix: Remove-Item "' + ps1Path + '" — PowerShell will fall back to squad.cmd which works fine.',
+  };
+}
+
 // ── ESM compatibility checks ────────────────────────────────────────
 
 // ── environment checks ─────────────────────────────────────────────
@@ -455,10 +482,14 @@ export async function runDoctor(cwd?: string): Promise<DoctorCheck[]> {
   // 11. Node.js version (node:sqlite availability)
   checks.push(checkNodeVersion());
 
-  // 11-12. ESM compatibility (Node 22/24+)
+  // 12-13. ESM compatibility (Node 22/24+)
   checks.push(checkVscodeJsonrpcExports(resolvedCwd));
   checks.push(checkCopilotSdkSessionPatch(resolvedCwd));
 
+  // 14. Windows .ps1 shim warning (#758)
+  const ps1Check = checkWindowsPs1Shim();
+  if (ps1Check) checks.push(ps1Check);
+
   return checks;
 }
 
diff --git a/test/cli/doctor.test.ts b/test/cli/doctor.test.ts
index 68cebb4c0..12673f554 100644
--- a/test/cli/doctor.test.ts
+++ b/test/cli/doctor.test.ts
@@ -11,7 +11,7 @@ import { mkdir, rm, writeFile } from 'fs/promises';
 import { join } from 'path';
 import { existsSync } from 'fs';
 import { randomBytes } from 'crypto';
-import { runDoctor, getDoctorMode, checkNodeVersion } from '@bradygaster/squad-cli/commands/doctor';
+import { runDoctor, getDoctorMode, checkNodeVersion, checkWindowsPs1Shim } from '@bradygaster/squad-cli/commands/doctor';
 import type { DoctorCheck } from '@bradygaster/squad-cli/commands/doctor';
 
 const TEST_ROOT = join(process.cwd(), `.test-doctor-${randomBytes(4).toString('hex')}`);
@@ -68,8 +68,12 @@ describe('squad doctor', () => {
 
     const squadDirCheck = checks.find((c: DoctorCheck) => c.name === '.squad/ directory exists');
     expect(squadDirCheck?.status).toBe('fail');
-    // When .squad/ is missing the file checks are skipped — .squad/ + squad.agent.md + Node version + 2 ESM checks
-    expect(checks.length).toBe(5);
+    // When .squad/ is missing the file checks are skipped — .squad/ + squad.agent.md + Node version + 2 ESM checks = 5
+    // On Windows, the .ps1 shim check may add one more if squad.ps1 exists
+    const baseCount = 5;
+    const ps1Check = checks.find((c: DoctorCheck) => c.name === 'Windows PowerShell shim');
+    const expectedCount = ps1Check ? baseCount + 1 : baseCount;
+    expect(checks.length).toBe(expectedCount);
   });
 
   it('detects remote mode from config.json with teamRoot', async () => {
@@ -289,4 +293,95 @@ describe('squad doctor', () => {
     expect(agentMdCheck?.status).toBe('fail');
     expect(agentMdCheck?.message).toContain('squad upgrade');
   });
+
+  // ── #758 — Windows .ps1 shim detection ────────────────────────────
+
+  it('checkWindowsPs1Shim returns undefined on non-Windows', () => {
+    const originalPlatform = Object.getOwnPropertyDescriptor(process, 'platform');
+    Object.defineProperty(process, 'platform', { value: 'linux', configurable: true });
+    try {
+      const result = checkWindowsPs1Shim();
+      expect(result).toBeUndefined();
+    } finally {
+      if (originalPlatform) {
+        Object.defineProperty(process, 'platform', originalPlatform);
+      }
+    }
+  });
+
+  it('checkWindowsPs1Shim returns warn when .ps1 file exists on Windows', async () => {
+    const originalPlatform = Object.getOwnPropertyDescriptor(process, 'platform');
+    const originalEnv = { ...process.env };
+
+    // Create a fake npm prefix directory with a squad.ps1 file
+    const fakeNpmPrefix = join(TEST_ROOT, 'fake-npm');
+    await mkdir(fakeNpmPrefix, { recursive: true });
+    await writeFile(join(fakeNpmPrefix, 'squad.ps1'), '# fake shim');
+
+    Object.defineProperty(process, 'platform', { value: 'win32', configurable: true });
+    process.env['npm_config_prefix'] = fakeNpmPrefix;
+
+    try {
+      const result = checkWindowsPs1Shim();
+      expect(result).toBeDefined();
+      expect(result?.status).toBe('warn');
+      expect(result?.name).toBe('Windows PowerShell shim');
+      expect(result?.message).toContain('squad.ps1');
+      expect(result?.message).toContain('Remove-Item');
+    } finally {
+      if (originalPlatform) {
+        Object.defineProperty(process, 'platform', originalPlatform);
+      }
+      process.env = originalEnv;
+    }
+  });
+
+  it('checkWindowsPs1Shim returns undefined when no .ps1 file found on Windows', async () => {
+    const originalPlatform = Object.getOwnPropertyDescriptor(process, 'platform');
+    const originalEnv = { ...process.env };
+
+    // Create a fake npm prefix directory WITHOUT squad.ps1
+    const fakeNpmPrefix = join(TEST_ROOT, 'fake-npm-empty');
+    await mkdir(fakeNpmPrefix, { recursive: true });
+
+    Object.defineProperty(process, 'platform', { value: 'win32', configurable: true });
+    process.env['npm_config_prefix'] = fakeNpmPrefix;
+
+    try {
+      const result = checkWindowsPs1Shim();
+      expect(result).toBeUndefined();
+    } finally {
+      if (originalPlatform) {
+        Object.defineProperty(process, 'platform', originalPlatform);
+      }
+      process.env = originalEnv;
+    }
+  });
+
+  it('checkWindowsPs1Shim falls back to APPDATA when npm_config_prefix is unset', async () => {
+    const originalPlatform = Object.getOwnPropertyDescriptor(process, 'platform');
+    const originalEnv = { ...process.env };
+
+    // Create fake APPDATA/npm with squad.ps1
+    const fakeAppData = join(TEST_ROOT, 'fake-appdata');
+    const fakeNpmDir = join(fakeAppData, 'npm');
+    await mkdir(fakeNpmDir, { recursive: true });
+    await writeFile(join(fakeNpmDir, 'squad.ps1'), '# fake shim');
+
+    Object.defineProperty(process, 'platform', { value: 'win32', configurable: true });
+    delete process.env['npm_config_prefix'];
+    process.env['APPDATA'] = fakeAppData;
+
+    try {
+      const result = checkWindowsPs1Shim();
+      expect(result).toBeDefined();
+      expect(result?.status).toBe('warn');
+      expect(result?.message).toContain(fakeNpmDir);
+    } finally {
+      if (originalPlatform) {
+        Object.defineProperty(process, 'platform', originalPlatform);
+      }
+      process.env = originalEnv;
+    }
+  });
 });