diff --git a/.changeset/fix-3362-windows-powershell-gemini.md b/.changeset/fix-3362-windows-powershell-gemini.md
new file mode 100644
index 000000000..159d9168f
--- /dev/null
+++ b/.changeset/fix-3362-windows-powershell-gemini.md
@@ -0,0 +1,6 @@
+---
+type: Fixed
+pr: 3368
+---
+
+**Gemini install output is valid on Windows PowerShell** - managed hook commands now use PowerShell's call operator when invoking quoted Node runners on Windows, and reinstall rewrites existing managed hooks without double-prefixing them. Gemini agent conversion also drops Claude-only `AskUserQuestion` / `ask_user` tool metadata and rewrites body references to runtime-neutral prompt wording. Fixes #3362.
diff --git a/bin/install.js b/bin/install.js
index 6095e9b15..f08396e14 100755
--- a/bin/install.js
+++ b/bin/install.js
@@ -594,8 +594,15 @@ function resolveNodeRunner() {
  *
  * Returns true if any entry was rewritten.
  */
-function rewriteLegacyManagedNodeHookCommands(settings, absoluteRunner) {
+function formatHookCommandForShell(command, opts) {
+  const platform = (opts && opts.platform) || process.platform;
+  return platform === 'win32' ? `& ${command}` : command;
+}
+
+function rewriteLegacyManagedNodeHookCommands(settings, absoluteRunner, opts) {
   if (!settings || !settings.hooks || !absoluteRunner) return false;
+  if (!opts) opts = {};
+  const platform = opts.platform || process.platform;
   const MANAGED_HOOK_FILES = new Set([
     'gsd-check-update.js',
     'gsd-statusline.js',
@@ -613,7 +620,11 @@ function rewriteLegacyManagedNodeHookCommands(settings, absoluteRunner) {
       if (!entry || !Array.isArray(entry.hooks)) continue;
       for (const h of entry.hooks) {
         if (!h || typeof h.command !== 'string') continue;
-        const trimmed = h.command.trim();
+        let trimmed = h.command.trim();
+        const hadPowerShellCallOperator = platform === 'win32' && /^&\s+/.test(trimmed);
+        if (hadPowerShellCallOperator) {
+          trimmed = trimmed.replace(/^&\s+/, '').trim();
+        }
         // Match two runner forms:
         //   1. Legacy bare-node form: `node <script>` (#2979/#3002)
         //   2. Cellar-path form: `"/usr/local/Cellar/node/<v>/bin/node" <script>`
@@ -642,8 +653,10 @@ function rewriteLegacyManagedNodeHookCommands(settings, absoluteRunner) {
           runnerToken = m[1];
           const runnerPath = (m[2] || m[3] || m[4] || '').replace(/\\/g, '/');
           const stableRunner = normalizeNodePath(runnerPath);
-          // Only process if the runner IS a Cellar path that normalizes to something different
-          if (stableRunner === runnerPath) continue;
+          // Process Cellar paths so they normalize to a stable symlink. On
+          // Windows, also process already-absolute runners so PowerShell gets
+          // the call operator needed to invoke a quoted executable path (#3362).
+          if (stableRunner === runnerPath && platform !== 'win32') continue;
           scriptToken = m[5];
           scriptPath = m[6] || m[7] || m[8] || '';
         }
@@ -654,10 +667,12 @@ function rewriteLegacyManagedNodeHookCommands(settings, absoluteRunner) {
         const scriptBase = scriptPath.split(/[\\/]/).pop() || '';
         if (!MANAGED_HOOK_FILES.has(scriptBase)) continue;
 
-        // Skip if already using the desired stable runner
-        if (runnerToken !== 'node' && runnerToken === absoluteRunner) continue;
+        // Skip if already using the desired stable runner.
+        if (runnerToken !== 'node' && runnerToken === absoluteRunner) {
+          if (platform !== 'win32' || hadPowerShellCallOperator) continue;
+        }
 
-        h.command = `${absoluteRunner} ${scriptToken}`;
+        h.command = formatHookCommandForShell(`${absoluteRunner} ${scriptToken}`, opts);
         changed = true;
       }
     }
@@ -835,10 +850,11 @@ function cleanupLegacyCodexHooksJson(targetDir) {
  *
  * @param {string} configDir - Resolved absolute config directory path
  * @param {string} hookName - Hook filename (e.g. 'gsd-statusline.js')
- * @param {{ portableHooks?: boolean }} [opts] - Options
+ * @param {{ portableHooks?: boolean, platform?: NodeJS.Platform }} [opts] - Options
  *   portableHooks: when true, emit $HOME-relative paths instead of absolute paths.
  *   Safe for Linux/macOS global installs and WSL/Docker bind-mount scenarios.
  *   Not suitable for pure Windows (cmd.exe/PowerShell do not expand $HOME).
+ *   platform: test injection for shell command formatting. Defaults to process.platform.
  */
 function buildHookCommand(configDir, hookName, opts) {
   if (!opts) opts = {};
@@ -867,12 +883,12 @@ function buildHookCommand(configDir, hookName, opts) {
     const relative = normalized.startsWith(home)
       ? '$HOME' + normalized.slice(home.length)
       : normalized;
-    return `${runner} "${relative}/hooks/${hookName}"`;
+    return formatHookCommandForShell(`${runner} "${relative}/hooks/${hookName}"`, opts);
   }
 
   // Default: absolute path with forward slashes (Windows-safe, fixes #2045/#2046).
   const hooksPath = configDir.replace(/\\/g, '/') + '/hooks/' + hookName;
-  return `${runner} "${hooksPath}"`;
+  return formatHookCommandForShell(`${runner} "${hooksPath}"`, opts);
 }
 
 /**
@@ -1285,7 +1301,6 @@ const claudeToGeminiTools = {
   WebSearch: 'google_web_search',
   WebFetch: 'web_fetch',
   TodoWrite: 'write_todos',
-  AskUserQuestion: 'ask_user',
 };
 
 /**
@@ -1318,8 +1333,15 @@ function convertGeminiToolName(claudeTool) {
   if (claudeTool.startsWith('mcp__')) {
     return null;
   }
-  // Task/Agent: exclude — agents are auto-registered as callable tools
-  if (claudeTool === 'Task' || claudeTool === 'Agent') {
+  // Task/Agent: exclude — agents are auto-registered as callable tools.
+  // AskUserQuestion: exclude — Gemini CLI does not expose an ask_user tool;
+  // emitting it causes frontmatter validation errors (#3362).
+  if (
+    claudeTool === 'Task' ||
+    claudeTool === 'Agent' ||
+    claudeTool === 'AskUserQuestion' ||
+    claudeTool === 'ask_user'
+  ) {
     return null;
   }
   // Check for explicit mapping
@@ -4810,6 +4832,10 @@ function convertSlashCommandsToGeminiMentions(content) {
 function convertClaudeToGeminiMarkdown(content, { isCommand = false } = {}) {
   // Apply Gemini-specific slash command namespacing
   let converted = convertSlashCommandsToGeminiMentions(content);
+  // Gemini CLI does not expose Claude's AskUserQuestion tool. Convert body
+  // references to runtime-neutral wording so converted agents do not instruct
+  // Gemini to call a nonexistent tool (#3362).
+  converted = converted.replace(/\b(?:AskUserQuestion|ask_user)\b/g, 'conversational prompting');
   // Strip HTML subscript tags — terminals can't render them. Done before
   // TOML conversion so the prompt body of a command file is also clean.
   converted = stripSubTags(converted);
@@ -8777,7 +8803,7 @@ function install(isGlobal, runtime = 'claude') {
   // `node` command that recreates the #2979 failure.
   const localCmd = (hookFile) => localNodeRunner === null
     ? null
-    : localNodeRunner + ' ' + localPrefix + '/hooks/' + hookFile;
+    : formatHookCommandForShell(localNodeRunner + ' ' + localPrefix + '/hooks/' + hookFile, hookOpts);
   const statuslineCommand = isGlobal
     ? buildHookCommand(targetDir, 'gsd-statusline.js', hookOpts)
     : localCmd('gsd-statusline.js');
diff --git a/docs/context-monitor.md b/docs/context-monitor.md
index b6cd21cf9..32dbf50c0 100644
--- a/docs/context-monitor.md
+++ b/docs/context-monitor.md
@@ -65,13 +65,15 @@ Both hooks are automatically registered during `npx get-shit-done-cc` installati
 - **Statusline** (writes bridge file): Registered as `statusLine` in settings.json
 - **Context Monitor** (reads bridge file): Registered as `PostToolUse` hook in settings.json (`AfterTool` for Gemini)
 
+Manual registration should use the absolute Node executable path that ran the installer. On Windows PowerShell, prefix the command with `&` when that executable path is quoted.
+
 Manual registration in `~/.claude/settings.json` (Claude Code):
 
 ```json
 {
   "statusLine": {
     "type": "command",
-    "command": "node ~/.claude/hooks/gsd-statusline.js"
+    "command": "\"/usr/local/bin/node\" \"/Users/me/.claude/hooks/gsd-statusline.js\""
   },
   "hooks": {
     "PostToolUse": [
@@ -79,7 +81,7 @@ Manual registration in `~/.claude/settings.json` (Claude Code):
         "hooks": [
           {
             "type": "command",
-            "command": "node ~/.claude/hooks/gsd-context-monitor.js"
+            "command": "\"/usr/local/bin/node\" \"/Users/me/.claude/hooks/gsd-context-monitor.js\""
           }
         ]
       }
@@ -98,7 +100,7 @@ For Gemini CLI (`~/.gemini/settings.json`), use `AfterTool` instead of `PostTool
         "hooks": [
           {
             "type": "command",
-            "command": "node ~/.gemini/hooks/gsd-context-monitor.js"
+            "command": "& \"C:/Program Files/nodejs/node.exe\" \"C:/Users/me/.gemini/hooks/gsd-context-monitor.js\""
           }
         ]
       }
diff --git a/tests/bug-2979-hook-absolute-node.test.cjs b/tests/bug-2979-hook-absolute-node.test.cjs
index da81f6d63..e0e4a1332 100644
--- a/tests/bug-2979-hook-absolute-node.test.cjs
+++ b/tests/bug-2979-hook-absolute-node.test.cjs
@@ -103,6 +103,26 @@ describe('Bug #2979: buildHookCommand for .js hooks emits absolute node runner',
   });
 });
 
+describe('Bug #3362: Windows PowerShell hook commands use the call operator', () => {
+  test('global install: .js hook command starts with & so quoted runners execute in PowerShell', () => {
+    const cmd = buildHookCommand('C:/Program Files/Gemini/.gemini', 'gsd-check-update.js', {
+      platform: 'win32',
+    });
+    assert.ok(cmd.startsWith('& '), `PowerShell commands need call operator, got: ${cmd}`);
+    assert.ok(cmd.includes('"C:/Program Files/Gemini/.gemini/hooks/gsd-check-update.js"'));
+  });
+
+  test('portable install: .js hook command also uses & on Windows PowerShell', () => {
+    const home = require('node:os').homedir().replace(/\\/g, '/');
+    const cmd = buildHookCommand(`${home}/.gemini`, 'gsd-check-update.js', {
+      portableHooks: true,
+      platform: 'win32',
+    });
+    assert.ok(cmd.startsWith('& '), `PowerShell commands need call operator, got: ${cmd}`);
+    assert.equal(parseHookCommand(cmd.slice(2)).hookPath, '$HOME/.gemini/hooks/gsd-check-update.js');
+  });
+});
+
 describe('Bug #2979: buildHookCommand for .sh hooks still uses bare "bash" (POSIX std PATH always has /bin)', () => {
   test('.sh hook runner is exactly "bash" — bash is in /usr/bin:/bin and resolves under minimal PATH', () => {
     const cmd = buildHookCommand('/tmp/.claude', 'gsd-session-state.sh');
@@ -154,6 +174,55 @@ describe('Bug #2979 (#3002 CR): rewriteLegacyManagedNodeHookCommands rewrites ba
     assert.equal(settings.hooks.SessionStart[0].hooks[0].command, before);
   });
 
+  test('adds PowerShell call operator to existing quoted managed hooks on Windows', () => {
+    const settings = {
+      hooks: {
+        SessionStart: [{
+          hooks: [{ type: 'command', command: '"/usr/local/bin/node" "C:/Program Files/Gemini/.gemini/hooks/gsd-check-update.js"' }],
+        }],
+      },
+    };
+    const runner = '"/usr/local/bin/node"';
+    const changed = rewriteLegacyManagedNodeHookCommands(settings, runner, { platform: 'win32' });
+    assert.equal(changed, true);
+    assert.equal(
+      settings.hooks.SessionStart[0].hooks[0].command,
+      '& "/usr/local/bin/node" "C:/Program Files/Gemini/.gemini/hooks/gsd-check-update.js"',
+    );
+  });
+
+  test('does NOT double-prefix managed hooks that already use the PowerShell call operator', () => {
+    const settings = {
+      hooks: {
+        SessionStart: [{
+          hooks: [{ type: 'command', command: '& "/usr/local/bin/node" "C:/Program Files/Gemini/.gemini/hooks/gsd-check-update.js"' }],
+        }],
+      },
+    };
+    const runner = '"/usr/local/bin/node"';
+    const before = settings.hooks.SessionStart[0].hooks[0].command;
+    const changed = rewriteLegacyManagedNodeHookCommands(settings, runner, { platform: 'win32' });
+    assert.equal(changed, false);
+    assert.equal(settings.hooks.SessionStart[0].hooks[0].command, before);
+  });
+
+  test('rewrites PowerShell bare-node managed hooks to absolute runner without dropping &', () => {
+    const settings = {
+      hooks: {
+        SessionStart: [{
+          hooks: [{ type: 'command', command: '& node "C:/Users/me/.gemini/hooks/gsd-check-update.js"' }],
+        }],
+      },
+    };
+    const runner = '"/usr/local/bin/node"';
+    const changed = rewriteLegacyManagedNodeHookCommands(settings, runner, { platform: 'win32' });
+    assert.equal(changed, true);
+    assert.equal(
+      settings.hooks.SessionStart[0].hooks[0].command,
+      '& "/usr/local/bin/node" "C:/Users/me/.gemini/hooks/gsd-check-update.js"',
+    );
+  });
+
   test('does NOT touch user-authored bare-node hooks (filename not in managed allowlist)', () => {
     const settings = {
       hooks: {
diff --git a/tests/gemini-namespacing.test.cjs b/tests/gemini-namespacing.test.cjs
index 04383225d..a3459be1b 100644
--- a/tests/gemini-namespacing.test.cjs
+++ b/tests/gemini-namespacing.test.cjs
@@ -18,6 +18,7 @@ const { createTempDir, cleanup } = require('./helpers.cjs');
 const {
   convertSlashCommandsToGeminiMentions,
   convertClaudeToGeminiMarkdown,
+  convertClaudeToGeminiAgent,
   _resetGsdCommandRoster,
   install
 } = require('../bin/install.js');
@@ -132,6 +133,24 @@ describe('Gemini Markdown Processor', () => {
     assert.doesNotMatch(result, /<sub>|<\/sub>/, '<sub> tags must be stripped');
     assert.match(result, /\/gsd:help/, 'slash command must still be converted');
   });
+
+  test('removes AskUserQuestion and ask_user from Gemini agent tools and body (#3362)', () => {
+    const input = [
+      '---',
+      'name: tester',
+      'tools: Read, AskUserQuestion, ask_user',
+      '---',
+      'Use AskUserQuestion or ask_user to ask the user.'
+    ].join('\n');
+
+    const result = convertClaudeToGeminiAgent(input);
+
+    assert.match(result, /^  - read_file$/m, 'Read should still map to Gemini read_file');
+    assert.doesNotMatch(result, /^  - ask_user$/m, 'ask_user must not be emitted as a Gemini tool');
+    assert.doesNotMatch(result, /\bAskUserQuestion\b/, 'Claude tool references must be neutralized');
+    assert.doesNotMatch(result, /\bask_user\b/, 'lowercase ask_user references must be neutralized');
+    assert.match(result, /conversational prompting/, 'body should use runtime-neutral wording');
+  });
 });
 
 describe('Gemini Install (Behavioral)', () => {
diff --git a/tests/runtime-converters.test.cjs b/tests/runtime-converters.test.cjs
index ad47e6bea..a799a62b7 100644
--- a/tests/runtime-converters.test.cjs
+++ b/tests/runtime-converters.test.cjs
@@ -265,7 +265,7 @@ Use \${PHASE} in shell examples.
     assert.ok(!result.includes('${PHASE}'), 'removes Gemini template-string pattern');
   });
 
-  test('excludes Claude agent dispatcher tools from Gemini frontmatter', () => {
+  test('excludes Claude-only agent interaction tools from Gemini frontmatter', () => {
     const input = `---
 name: gsd-debug-session-manager
 description: Manages debug sessions.
@@ -274,17 +274,21 @@ tools: Read, Task, Agent, AskUserQuestion
 
 <role>
 Coordinate debugger agents.
+Offer choices via AskUserQuestion when user input is needed.
 </role>`;
 
     const result = convertClaudeToGeminiAgent(input);
     const frontmatter = result.split('---')[1] || '';
 
     assert.ok(frontmatter.includes('  - read_file'), 'maps Read -> read_file');
-    assert.ok(frontmatter.includes('  - ask_user'), 'maps AskUserQuestion -> ask_user');
+    assert.ok(!frontmatter.includes('  - ask_user'), 'does not emit invalid Gemini ask_user tool');
     assert.ok(!frontmatter.includes('  - task'), 'does not emit invalid Gemini task tool');
     assert.ok(!frontmatter.includes('  - agent'), 'does not emit invalid Gemini agent tool');
     assert.ok(!frontmatter.includes('Task'), 'does not preserve Claude-only Task tool');
     assert.ok(!frontmatter.includes('Agent'), 'does not preserve Claude-only Agent tool');
+    assert.ok(!frontmatter.includes('AskUserQuestion'), 'does not preserve Claude-only AskUserQuestion tool');
+    assert.ok(!result.includes('AskUserQuestion'), 'does not leave Claude-only tool references in the body');
+    assert.ok(result.includes('conversational prompting'), 'uses runtime-neutral body wording for user prompts');
   });
 });