You could also log onto to Norton and scan from the web, takes a time but usually works, however, some virus's look for Norton and destroy it so you might like to try others. Proland Plus and PC Cillian can both be downloaded on a trial basis and also scan from their web site.
I have used Norton for 3 years, but twice (once a couple of weeks ago) it let a virus through so don't think you are safe just cos Norton says so. If in doubt try one of the others. Also if you go onto Virus sites, you can generally type in the virus you have and download the particular fix and instructions. . . . . . . . . . . . . . . . . . . . . .Personally I wonder why all the decent computer users can't contribute / club together for a fund to seek retribution on the a"seoles who create virus's. It strikes me with a big enough pot of gold anyone would bubble up a "friend" boasting of virus creation.