diff --git a/test/test-installation-components.js b/test/test-installation-components.js
index 1317bbbf5..f511b4376 100644
--- a/test/test-installation-components.js
+++ b/test/test-installation-components.js
@@ -3456,6 +3456,125 @@ async function runTests() {
 
   console.log('');
 
+  // ============================================================
+  // Test Suite 47: WSL shell using Windows Node guard
+  // ============================================================
+  console.log(`${colors.yellow}Test Suite 47: WSL Windows Node guard${colors.reset}\n`);
+
+  try {
+    const wslNodeCheck = require('../tools/installer/core/wsl-node-check');
+
+    let detection = wslNodeCheck.detectWindowsNodeFromWsl({
+      platform: 'win32',
+      env: { WSL_DISTRO_NAME: 'Ubuntu-26.04' },
+      cwd: String.raw`C:\Windows`,
+      execPath: String.raw`C:\Program Files\nodejs\node.exe`,
+    });
+    assert(detection.isMismatch === true, 'detects Windows Node launched from WSL via WSL_DISTRO_NAME');
+
+    detection = wslNodeCheck.detectWindowsNodeFromWsl({
+      platform: 'win32',
+      env: { PWD: '/home/devuser/projects/md2pdf' },
+      cwd: String.raw`\\wsl.localhost\Ubuntu-26.04\home\devuser\projects\md2pdf`,
+      execPath: String.raw`C:\Program Files\nodejs\node.exe`,
+    });
+    assert(detection.isMismatch === true, 'detects Windows Node launched from WSL via Linux PWD / WSL UNC cwd');
+
+    detection = wslNodeCheck.detectWindowsNodeFromWsl({
+      platform: 'win32',
+      env: {},
+      cwd: String.raw`\\wsl$\Ubuntu-26.04\home\devuser\projects\md2pdf`,
+      execPath: String.raw`C:\Program Files\nodejs\node.exe`,
+    });
+    assert(detection.isMismatch === true, 'detects Windows Node launched from WSL via legacy WSL UNC cwd');
+
+    detection = wslNodeCheck.detectWindowsNodeFromWsl({
+      platform: 'linux',
+      env: { WSL_DISTRO_NAME: 'Ubuntu-26.04', PWD: '/home/devuser/projects/md2pdf' },
+      cwd: '/home/devuser/projects/md2pdf',
+      execPath: '/usr/bin/node',
+    });
+    assert(detection.isMismatch === false, 'allows native Linux Node inside WSL');
+
+    detection = wslNodeCheck.detectWindowsNodeFromWsl({
+      platform: 'win32',
+      env: { PWD: String.raw`C:\Users\devuser\project` },
+      cwd: String.raw`C:\Users\devuser\project`,
+      execPath: String.raw`C:\Program Files\nodejs\node.exe`,
+    });
+    assert(detection.isMismatch === false, 'allows normal Windows Node outside WSL');
+
+    detection = wslNodeCheck.detectWindowsNodeFromWsl({
+      platform: 'win32',
+      env: { PWD: '/c/Users/devuser/project' },
+      cwd: String.raw`C:\Users\devuser\project`,
+      execPath: String.raw`C:\Program Files\nodejs\node.exe`,
+    });
+    assert(detection.isMismatch === false, 'allows Git Bash Windows-drive PWD outside WSL');
+
+    detection = wslNodeCheck.detectWindowsNodeFromWsl({
+      platform: 'win32',
+      env: { PWD: '/cygdrive/c/Users/devuser/project' },
+      cwd: String.raw`C:\Users\devuser\project`,
+      execPath: String.raw`C:\Program Files\nodejs\node.exe`,
+    });
+    assert(detection.isMismatch === false, 'allows Cygwin Windows-drive PWD outside WSL');
+
+    const message = wslNodeCheck.formatWindowsNodeFromWslMessage({
+      isMismatch: true,
+      reason: 'WSL_DISTRO_NAME is set',
+      execPath: String.raw`C:\Program Files\nodejs\node.exe`,
+    });
+    assert(message.includes('Install Node.js inside WSL'), 'guard message tells user to install Node.js inside WSL');
+    assert(message.includes(String.raw`C:\Program Files\nodejs\node.exe`), 'guard message includes detected Windows Node path');
+
+    const promptsModule = require('../tools/installer/prompts');
+    const real = {
+      detectWindowsNodeFromWsl: wslNodeCheck.detectWindowsNodeFromWsl,
+      log: promptsModule.log,
+      exit: process.exit,
+    };
+    const seen = { errors: [], exit: [] };
+    wslNodeCheck.detectWindowsNodeFromWsl = () => ({
+      isMismatch: true,
+      reason: 'WSL_INTEROP is set',
+      execPath: String.raw`C:\Program Files\nodejs\node.exe`,
+    });
+    promptsModule.log = {
+      error: async (m) => void seen.errors.push(m),
+      info: async () => {},
+      success: async () => {},
+      warn: async () => {},
+      message: async () => {},
+      step: async () => {},
+    };
+    process.exit = (code) => {
+      seen.exit.push(code);
+      throw new Error('__stub_exit__');
+    };
+
+    try {
+      let threw = false;
+      try {
+        await wslNodeCheck.checkWindowsNodeFromWsl();
+      } catch (error) {
+        threw = error.message === '__stub_exit__';
+      }
+      assert(threw && seen.exit[0] === 1, 'guard exits with code 1 when Windows Node is launched from WSL');
+      assert(seen.errors[0].includes('Windows Node.js was launched from a WSL shell'), 'guard logs the mismatch explanation');
+    } finally {
+      wslNodeCheck.detectWindowsNodeFromWsl = real.detectWindowsNodeFromWsl;
+      promptsModule.log = real.log;
+      process.exit = real.exit;
+    }
+  } catch (error) {
+    console.log(`${colors.red}Test Suite 47 setup failed: ${error.message}${colors.reset}`);
+    console.log(error.stack);
+    failed++;
+  }
+
+  console.log('');
+
   // ============================================================
   // Summary
   // ============================================================
diff --git a/tools/installer/commands/install.js b/tools/installer/commands/install.js
index 1dfe6fb70..42f6213de 100644
--- a/tools/installer/commands/install.js
+++ b/tools/installer/commands/install.js
@@ -75,6 +75,9 @@ module.exports = {
         return;
       }
 
+      const { checkWindowsNodeFromWsl } = require('../core/wsl-node-check');
+      await checkWindowsNodeFromWsl();
+
       // Set debug flag as environment variable for all components
       if (options.debug) {
         process.env.BMAD_DEBUG_MANIFEST = 'true';
diff --git a/tools/installer/core/wsl-node-check.js b/tools/installer/core/wsl-node-check.js
new file mode 100644
index 000000000..261ebf2d7
--- /dev/null
+++ b/tools/installer/core/wsl-node-check.js
@@ -0,0 +1,109 @@
+const prompts = require('../prompts');
+
+const WSL_UNC_PATTERN = /^\\\\wsl(?:\.localhost|\$)?\\/i;
+
+function normalizePath(value) {
+  return typeof value === 'string' ? value.replaceAll('/', '\\').toLowerCase() : '';
+}
+
+function isLinuxStylePath(value) {
+  return (
+    typeof value === 'string' &&
+    value.startsWith('/') &&
+    !value.startsWith('//') &&
+    !/^\/[a-z](?:\/|$)/i.test(value) &&
+    !/^\/cygdrive\/[a-z](?:\/|$)/i.test(value)
+  );
+}
+
+function isWslUncPath(value) {
+  return WSL_UNC_PATTERN.test(value || '');
+}
+
+/**
+ * Detect the broken interop case where WSL resolved node/npx to Windows.
+ * @param {Object} [runtime]
+ * @param {string} [runtime.platform]
+ * @param {Object} [runtime.env]
+ * @param {string} [runtime.cwd]
+ * @param {string} [runtime.execPath]
+ * @returns {{isMismatch: boolean, reason: string|null, execPath: string}}
+ */
+function detectWindowsNodeFromWsl(runtime = {}) {
+  const platform = runtime.platform || process.platform;
+  const env = runtime.env || process.env;
+  const cwd = runtime.cwd || safeCwd();
+  const execPath = runtime.execPath || process.execPath || '';
+
+  if (platform !== 'win32') {
+    return { isMismatch: false, reason: null, execPath };
+  }
+
+  if (env.WSL_DISTRO_NAME) {
+    return { isMismatch: true, reason: 'WSL_DISTRO_NAME is set', execPath };
+  }
+
+  if (env.WSL_INTEROP) {
+    return { isMismatch: true, reason: 'WSL_INTEROP is set', execPath };
+  }
+
+  if (isLinuxStylePath(env.PWD)) {
+    return { isMismatch: true, reason: 'PWD is a Linux path', execPath };
+  }
+
+  if (isWslUncPath(cwd)) {
+    return { isMismatch: true, reason: 'current directory is a WSL UNC path', execPath };
+  }
+
+  const normalizedExecPath = normalizePath(execPath);
+  if (normalizedExecPath.includes('\\wsl$\\') || normalizedExecPath.includes('\\wsl.localhost\\')) {
+    return { isMismatch: true, reason: 'Node executable path is under a WSL UNC path', execPath };
+  }
+
+  return { isMismatch: false, reason: null, execPath };
+}
+
+function safeCwd() {
+  try {
+    return process.cwd();
+  } catch {
+    return '';
+  }
+}
+
+function formatWindowsNodeFromWslMessage(detection) {
+  const lines = [
+    'Windows Node.js was launched from a WSL shell.',
+    '',
+    'This usually means Node.js is not installed inside the WSL distro, so WSL resolved `node`/`npx` to Windows.',
+    'The installer cannot safely continue because Linux paths may be interpreted as Windows paths.',
+    '',
+    'Install Node.js inside WSL, then rerun the same command from the WSL terminal.',
+  ];
+
+  if (detection.execPath) {
+    lines.push('', `Detected Node executable: ${detection.execPath}`);
+  }
+
+  if (detection.reason) {
+    lines.push(`Detection signal: ${detection.reason}`);
+  }
+
+  return lines.join('\n');
+}
+
+async function checkWindowsNodeFromWsl() {
+  const detection = module.exports.detectWindowsNodeFromWsl();
+  if (!detection.isMismatch) {
+    return detection;
+  }
+
+  await prompts.log.error(formatWindowsNodeFromWslMessage(detection));
+  process.exit(1);
+}
+
+module.exports = {
+  checkWindowsNodeFromWsl,
+  detectWindowsNodeFromWsl,
+  formatWindowsNodeFromWslMessage,
+};