Can you boot into safe mode?
If so... you can try removing the virus in safe mode with whatever antivirus program you have installed. You can boot into safe mode with networking so you can update the definitions... make sure you turn off system restore too.
If that doesn't work... slave the drive to another computer... save all of your important data... then download this program here that will zero your hard drive:
http://prdownloads.sourceforge.net/d...6.iso?download ... it is a ISO file... you just need to burn the image to a cd... hook the old hard drive back to your original system after backing it up... set the CD drive as the first boot device... save your setting changes and pop in your cd... reboot and boot from the CD you just made to wipe out the hard drive... after that is done... reinstall the OS and your all set to go.