diff --git a/desktop_engine.py b/desktop_engine.py
index 9ff3bf0..de73c91 100644
--- a/desktop_engine.py
+++ b/desktop_engine.py
@@ -28,6 +28,19 @@ def _pick_port():
 
 
 def _parent_alive(pid):
+    # Windows: os.kill(pid, 0) KHONG kiem tra ton tai — no goi
+    # TerminateProcess (giai thich: moi sig khac CTRL_C/BREAK deu terminate).
+    # => watchdog se GIET LUON tien trinh cha (Tauri) sau 1s dau tien.
+    # Dung OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION): tra ve NULL khi
+    # pid khong con ton tai.
+    if os.name == "nt":
+        import ctypes
+        PROCESS_QUERY_LIMITED_INFORMATION = 0x1000
+        h = ctypes.windll.kernel32.OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, False, pid)
+        if not h:
+            return False  # tien trinh da chet
+        ctypes.windll.kernel32.CloseHandle(h)
+        return True
     try:
         os.kill(pid, 0)
         return True
@@ -38,25 +51,31 @@ def _parent_alive(pid):
 def main():
     os.environ.setdefault("SF_DESKTOP", "1")
 
+    # Log dir tao SOM de stderr co the tro vao file (xem duoi).
+    log_dir = os.path.join(
+        os.environ.get("APPDATA") or os.path.expanduser("~"),
+        APP_DATA_DIR_NAME, "logs",
+    )
+    try:
+        os.makedirs(log_dir, exist_ok=True)
+    except OSError:
+        log_dir = os.path.expanduser("~")
+
     # Windowed app (engine.spec console=False): Windows khong tao console ->
     # sys.stdout/sys.stderr = None -> uvicorn logging crash
-    # ('NoneType' object has no attribute 'isatty'). Thay bang file rong de
-    # uvicorn (StreamHandler/isatty) luon co stream hop le.
+    # ('NoneType' object has no attribute 'isatty'). Tro stdout/stderr vao
+    # FILE (KHONG phai devnull) — neu devnull thi moi exception bi nuot im
+    # lang (trieu chung 'stuck khong logs, khong loi').
     if sys.stdout is None:
-        sys.stdout = open(os.devnull, "w")
+        sys.stdout = open(os.path.join(log_dir, "stdout.log"), "w", encoding="utf-8")
     if sys.stderr is None:
-        sys.stderr = open(os.devnull, "w")
+        sys.stderr = open(os.path.join(log_dir, "stderr.log"), "w", encoding="utf-8")
 
     port = _pick_port()
     os.environ["SF_PORT"] = str(port)
 
     # Log ra file — khi dong goi console=False, stdout khong nhin thay duoc.
     try:
-        log_dir = os.path.join(
-            os.environ.get("APPDATA") or os.path.expanduser("~"),
-            APP_DATA_DIR_NAME, "logs",
-        )
-        os.makedirs(log_dir, exist_ok=True)
         logging.basicConfig(
             level=logging.INFO,
             format="%(asctime)s %(levelname)s %(name)s: %(message)s",