http://www.microsoft.com/windowsxp/u...emrestore.mspx
If your computer can be turned on at all, you can use system restore to get the virus out. The link above explains how to do it for windows xp. If you have a different system, just google
system restore with the name of your operating system.
It won't do any harm to try this, and sometimes it works miracles.
The link above doesn't mention that you can also get to System Restore by turning your machine on and hitting (I think) F8 when the machine wakes up, which is handy in case nothing at all is accessible.