If you're really worried about viruses on a PC, you need to do 4 things: 1) Stop using internet explorer and setup a firewall 2) Download AVG 3) Stop downloading those e-mail attachments from Stacy the Buxom Babe and 4) Stop going to those websites late at night I've had my computer for 6 years, and never had a virus on it, and have used it constantly to browse online, take school classes, for my job, etc. Let your school decide what you need, and don't be the guy who leaves his sound on to play World of Warcraft in class.