Can anyone please help me. I have a Windows 7 Home Edition 64 bit operating system and I am experiencing unexpected shutdowns of the system. This tends to occur mainly when doing a virus check or doing a back up using some software called SyncBackSE. I have tried looking at the event log but it just says that the system has recovered from an unexpected shutdown, one of the reasons being a possible power failure. When I am present for the shutdown the PC starts up in safe mode and is usually alright for a while with me being able to do a number of back ups and virus checks. The virus checkers I have been using are Microsoft Essentials and I am now using BitDefender. I don't know if this would have anything to do with it or not, but I have 4KB of data in a bad sector of C:\ that cannot be recovered.