I have Windows 7 64 bit with Bitdefender installed. This morning I was playing a game when Bitdefender notification fired-up and said it has quarantined the SAM file and that the system needs to restart to complete "cleaning". I haplessly did what my antivirus instructed and now my PC won't boot. BSOD everytime it reaches the login screen telling me about Security Manager and Hardware Failure. Searching for SAM I discover this is a critical system file. Can't even get to system restore or safe mode due to BSOD. System repair is also useless as it now loops. Everytime I click it it merely refreshes and it's the same page. Help please.