Just before we went away, I did a full backup of my data drive on the PC. The PC then ate its system drive. Data safe, OS and applications toast. The drive is so trashed that the system doesn't even recognise it as a hard disk anymore. Believe me, these things can fail totally, without warning, leaving you with nothing. I spent today reinstalling Windows and enough apps to get me working again. When I'm done, I'm making sure I have a backup of the system drive as well!