Go in safe mode so windows only starts basic things during startup , hoping it won't start the virus . Then . . .
Three options
1. Delete virus program files , go to application settings ( C:\Documents and Settings\*younamehere*\application data ) and delete virus settings ( check the other accounts too just in cause )( Make sure you can see hidden folders ) , run CCleaner Portable on a flash drive . Clean Computer, Clean Registry , Remove virus startup item if any
2. Try scanning your computer when in safe mode with USB Drive Antivirus 3.0 if you can INSTALL an antivirus such as AVG in safe mode , then do that and before scanning, update virus definitions !
3. If the top doesn't work well . . . wait until I get another idea , I used two had a virus like you , but I had to hard drives with XP on one and 7 on one so I used Shaw Secure on the XP one and scanned the 7 one and removed the virus safely
Good luck bro ! And try telling me the name of the program , it would help