diff --git a/lib_results_logger.py b/lib_results_logger.py
index a33df50..9c81b89 100644
--- a/lib_results_logger.py
+++ b/lib_results_logger.py
@@ -7,10 +7,19 @@ Appends task completion results to results.json in real-time.
 import json
 import os
 import time
-import fcntl
+import platform
 from pathlib import Path
 from typing import Dict, Any, Optional
 
+# Import fcntl only on Unix-like systems (Linux, macOS)
+# On Windows, we'll use msvcrt for file locking
+if platform.system() != "Windows":
+    import fcntl
+    HAS_FCNTL = True
+else:
+    import msvcrt
+    HAS_FCNTL = False
+
 
 def extract_domain_from_path(result_path: str) -> str:
     """
@@ -66,8 +75,12 @@ def append_task_result(
     # Thread-safe JSON append with file locking
     try:
         with open(results_file, 'a+') as f:
-            # Lock the file for exclusive access
-            fcntl.flock(f.fileno(), fcntl.LOCK_EX)
+            # Lock the file for exclusive access (platform-specific)
+            if HAS_FCNTL:
+                fcntl.flock(f.fileno(), fcntl.LOCK_EX)
+            else:
+                # Windows file locking using msvcrt
+                msvcrt.locking(f.fileno(), msvcrt.LK_LOCK, 1)
             
             try:
                 # Move to beginning to read existing content
@@ -95,8 +108,12 @@ def append_task_result(
                 f.write('\n')  # Add newline for readability
                 
             finally:
-                # Always unlock the file
-                fcntl.flock(f.fileno(), fcntl.LOCK_UN)
+                # Always unlock the file (platform-specific)
+                if HAS_FCNTL:
+                    fcntl.flock(f.fileno(), fcntl.LOCK_UN)
+                else:
+                    # Windows unlock using msvcrt
+                    msvcrt.locking(f.fileno(), msvcrt.LK_UNLCK, 1)
                 
         print(f"📝 Logged result: {domain}/{task_id} -> {result_entry['status']} (score: {score})")