Yep safe mode may work it usually does, but if it does not then close down the process that is using it, control/alt/delete together see what processes are running and close one down at a time when uou close one go to the file try and delete, if it does not close another process down go to the file again, eventually you will be able to delete it.
Do not close EXPLORER.EXE. and SYS TRAY.
Also you can follow this from microsoft
http://support.microsoft.com/default...b;en-us;320081
Yours is cause 2. Just scroll down to were it says cause 2.