The message you wrote about is pretty common with XP machines and is not always a virus. For example I could cause this by having some USB printer plugged in after the restore.
XP fails again and again which brings up a good question. Should the machine's maker and Microsoft have cured this over the past decade?
I restored a computer to factory settings because I was having an issue with a virus. However now that I've done that and I boot the computer up and log on, the computer says "the system will now complete setup and restart automatically". The computer shuts down and restarts fine and I get the same message and it continues to restart itself after I log in. Any ideas how I can get this to stop?