I finally decided to pitch the anti virus program. I have used a bunch of them over the years, Norton, Mccaffee, Eztrust, Fprot and AVG. I have scanned the disk for years without finding a virus. The scans take hours, the downloading of fresh virus definitions slows the internet. The newer antiviruses (antivirii?) have moved beyond scanning the harddrive and now stay active all the time, soaking up CPU time, diskspace and RAM, inspecting web links, slowing the computer, and never catching anything. So I'm now running barefoot, no anti virus installed.
You have to be a little bit careful. I run a router on my cable modem. The router has a pretty solid firewall to keep the internet from infecting the computer thru the various holes in Windows XP security. I never click on email attachments. I don't file share. I don't use thumb drives. I have auto-run turned off. I don't use Internet Exploder. I'm a home user, I don't plug into a company network. I run Windows Update and install the patches regularly.
We will see how long this lasts.