The public computer at my work has auto updating Antivirus software, norton security software, AND Microsoft Anti- Spyware.
The sucker is LOADED with spyware and viruses. LOADED.
More spyware than viruses though, I can usually actually get rid of the viruses on it. I just don't have enough TIME to eliminate the spyware. One of them Dell specials with 128MB of Ram combined with Windows XP. The sucker takes most of one of my shifts even to run a spyware scan, much less remove anything (which it can very seldom successfully do for some reason, seems like it has processes running that protect and relaunch other processes, and that instantly reinstall anything removed.