Re: Virus :(
The "just run Linux" advice is easy to give, but often difficult to take. Remember, people, that the OS is the least important aspect of the computer to most users -- it's the applications that make the difference. The GIMP is not Photoshop; Inkscape is not Illustrator; Blender is not 3dsMax or Maya; OO.o Calc is not Excel. An easier answer, I suppose, would be "go Mac" -- but that's expensive (requires hardware as well as software) and disruptive to an established workflow (have you ever tried right-clicking on a Mac?).
Booting to Linux from a separate drive to fix a Windows virus can be a viable solution -- it is devilishly difficult to remove a virus that has patched itself into the OS you're using while trying to remove it.
Running antivirus programs in general can only protect you from known types of virus/malware. If you run into a new virus today, it really doesn't help that the signatures database and heuristics for your AV will be updated first thing tomorrow morning. In the meantime, you're operating with a false sense of security and likely to do things that invite new infections.
The best solution (although it's too late to help with the OP's problem) is to back up frequently, and to keep your executables well separated from your data. If you're rigorous about this, the worst that can ever happen (barring some major catastrophe that completely destroys your computer, your on-site backup drives and any off-site backups you may have) is that you lose a couple of hours work, or a new preference setting, or perhaps have to re-install a program you installed earlier that day.
“Beware of bugs in the above code; I have only proved it correct, not tried it.” --Donald Knuth
"It was as if its architects were given a perfectly good hammer and gleefully replied, 'neat! With this hammer, we can build a tool that can pound in nails.'" -- Alex Papadimoulis (on TheDailyWTF.com)