I had this before. It can do alot of dmg to the drive up to a point where even when clean, you may have to reinstall.
Your first stop should be this program.
http://noahdfear.geekstogo.com/
http://www.help2go.com/Tutorials/Spy...eFix.exe).html
Finishing off with a Panda Scan
http://www.pandasoftware.com/actives...an/ascan_2.asp
Then possibly another spyware/malware scanner.
Then a "fix" on hard drive. Using the error checking tab as you right-click your main drive.
Good luck, it's a bitch of a thing.