I had a Problem with my computer the other day too. I downloaded a Program to convert Avis to MPEG-2s and this program fucked up my pc. Everytime I booted my pc it was up for 5 seconds then BOOOM BSOD!! the wonderfull Blue Screen Of Death!
How I solved it? Easy
If you have Vista you can go back in time in your system: It changes everything back. Now I went to this application and set it to the time before i installed that converter. and there it goes, everything fine again.
So, do you know when you had that Virus from or what was the last program you installed before you had this Virus infection?
I have my Vista installed in german so I'll write it in german and try to translate it:
you go to "system steuerung" which is i believe simply "System" in english, then you click on "Sichern und Wiederherstellen" ("Secure and recreate"?), then you click on "Windows mittels Systemwiederherstellung reparieren" ( " Repair Windows with Systemrecreation" or something like it, in the top left corner ) then it loads, let it load, then eventually it will open this Systemrecreation window, there you click on "Weiter" (Ok or further what ever) then tick the box next to "Wiederherstellungspunkte anzeigen, die älter als 5 Tage sind" ("show recreationpoints older than 5 days" or something like it) and then choose the point where your computer was still alive ^^ Then let it load, it will recreate every System object which was there at the time.
If your only problem are the documents or files then you can try it anyway but it says that documents are neither changed nor deleted.
But I don't think its going to harm you, and its reversable
Hope I could help,
greets
Beeotch