diff --git a/claude/uclaude_updater.py b/claude/uclaude_updater.py
index 046f6ce..7fdc81c 100644
--- a/claude/uclaude_updater.py
+++ b/claude/uclaude_updater.py
@@ -69,6 +69,13 @@ def eprint(*args, **kwargs):
     print(*args, file=sys.stderr, **kwargs)
 
 
+def run_cmd(cmd, **kwargs):
+    """run_cmd wrapper: uses shell=True on Windows for .cmd/.bat commands (npm, claude, etc.)."""
+    if IS_WINDOWS:
+        kwargs.setdefault("shell", True)
+    return subprocess.run(cmd, **kwargs)
+
+
 # ============================================================
 #  Node.js check and auto-install
 # ============================================================
@@ -79,7 +86,7 @@ MIN_NODE_VERSION = (24, 13, 0)
 def get_node_version():
     """Get installed Node.js version as tuple, or None."""
     try:
-        result = subprocess.run(
+        result = run_cmd(
             ["node", "--version"],
             capture_output=True, text=True, timeout=10,
         )
@@ -103,7 +110,7 @@ def install_node():
     if IS_MACOS:
         print(f"  Installing Node.js via Homebrew...")
         try:
-            result = subprocess.run(
+            result = run_cmd(
                 ["brew", "install", "node"],
                 timeout=120, capture_output=True, text=True,
             )
@@ -125,7 +132,7 @@ def install_node():
             if os.path.isfile(old_list):
                 os.remove(old_list)
 
-        result = subprocess.run(
+        result = run_cmd(
             ["bash", "-c", "curl -fsSL https://deb.nodesource.com/setup_24.x | bash - && apt-get install -y nodejs"],
             timeout=180, capture_output=True, text=True,
         )
@@ -140,7 +147,7 @@ def install_node():
         # Try dnf/yum fallback for RHEL/Fedora
         for pkg_mgr in ["dnf", "yum"]:
             if shutil.which(pkg_mgr):
-                result = subprocess.run(
+                result = run_cmd(
                     ["bash", "-c", f"curl -fsSL https://rpm.nodesource.com/setup_24.x | bash - && {pkg_mgr} install -y nodejs"],
                     timeout=180, capture_output=True, text=True,
                 )
@@ -213,7 +220,7 @@ def ensure_claude_code(target_version=None):
         pkg = "@anthropic-ai/claude-code" + (f"@{target_version}" if target_version else "")
 
     try:
-        result = subprocess.run(
+        result = run_cmd(
             ["npm", "install", "-g", pkg],
             capture_output=True, text=True, timeout=300,
         )
@@ -291,7 +298,7 @@ def get_installed_version():
 
     # 2. claude --version
     try:
-        result = subprocess.run(
+        result = run_cmd(
             ["claude", "--version"],
             capture_output=True, text=True, timeout=10,
         )
@@ -362,13 +369,13 @@ def git_pull():
     """Pull latest changes from remote (shallow fetch for minimal download)."""
     try:
         # Shallow fetch + reset — downloads only latest commit, not full history
-        result = subprocess.run(
+        result = run_cmd(
             ["git", "fetch", "--depth", "1", "origin", "master"],
             cwd=REPO_ROOT, capture_output=True, text=True, timeout=60,
         )
         if result.returncode != 0:
             # Fallback to regular pull
-            result = subprocess.run(
+            result = run_cmd(
                 ["git", "pull", "--quiet"],
                 cwd=REPO_ROOT, capture_output=True, text=True, timeout=60,
             )
@@ -377,7 +384,7 @@ def git_pull():
             return True
 
         # Reset to fetched state
-        subprocess.run(
+        run_cmd(
             ["git", "reset", "--hard", "origin/master"],
             cwd=REPO_ROOT, capture_output=True, text=True, timeout=10,
         )
@@ -414,7 +421,7 @@ def _setup_sparse_checkout():
         return
 
     # Enable sparse checkout
-    subprocess.run(
+    run_cmd(
         ["git", "config", "core.sparseCheckout", "true"],
         cwd=REPO_ROOT, capture_output=True,
     )
@@ -432,7 +439,7 @@ def _setup_sparse_checkout():
         f.write("\n".join(patterns) + "\n")
 
     # Apply sparse checkout
-    subprocess.run(
+    run_cmd(
         ["git", "checkout", "HEAD", "--", "."],
         cwd=REPO_ROOT, capture_output=True, timeout=30,
     )
@@ -461,7 +468,7 @@ def install_cli_js(version, cli_js_path):
         os.chmod(cli_js_path, 0o755)
 
         # Syntax check
-        result = subprocess.run(
+        result = run_cmd(
             ["node", "--check", cli_js_path],
             capture_output=True, text=True, timeout=30,
         )
@@ -748,7 +755,7 @@ def _set_user_env_windows(config):
 
     for key, val in env_vars.items():
         try:
-            subprocess.run(["setx", key, val], capture_output=True, check=True)
+            run_cmd(["setx", key, val], capture_output=True, check=True)
             os.environ[key] = val
         except Exception:
             pass