First, tell us if you're running it with or without hacks? Reinstall the game (if you downloaded it as torrent, maybe some files missing in the folder).
1. Run as admin if you have Windows 7 or Vista
2. Maybe your firewall blocking it, so check firewall settings
3. Where do you live (download EU version if you're in Europe)
Also check this thread on BS official forums: Gamegaurd error 380 with no fix - Blackshot Forum