This looks and smells like a runtime viral infection, you can probably run as many av scanners as you wan`t while booted into the system but it will still probably come back. Possibly Emsisoft`s emergency USB stick ran in Safe-Mode
http://www.emsisoft.com/en/software/download/ Deep scan.
Also download Avira`s rescue cd, boot into that and scan
http://www.free-av.com/en/products/1...ue_system.html it`s free.
Only other thing is to go the Combofix/OLT route but your better of doing that via Bleeping. My guess is there`s a hidden root kit snuck somewhere...