According to my IT son, who maintains a network of over 50 computers:
"It sounds like a BHO or Browser Hijack. I suggest he runs AdAware or Bulletproof Spyware Removal to search his hard drive for any kind of BHO's or spy-ware."

Also, there was an issue with ie6. Go back and check Windows Update and see if you need to uninstall IE6 and reinstall it.

The virus thing sounds like a real possibility, Scott. Good luck.