Re: I think I have a virus.
What AV are you using? How many processes are running in the background? Dunno if Vista has the msconfig command, but you need to see what is trying to run on your PC. If it does, look at the startup tab and uncheck everything except your AV. Check your startup folder and see what's in there. Have you installed any new software recently?
Change the world. Of one person. Today.
If your equation requires either a complex combination of variables to get the desired result OR you can't seem to get the result regardless of the variables....it ain't your variables, it's your constant.