Install Spybot Search and Destroy on that machine. Reboot the computer in Safe Mode without Networking and let Spybot do its thing. Remove everything it finds.
Also, Run HiJakk This! And save the log. Find a forum with security experts and post that log to them. Never ever remove stuff from a Hijakk log without the qualified advice of a security expert or you may ruin the machine even more!
Hp a330n XP w\SP2. This my dads machine. He is unable to set his background. Can't right click and wallpaper. His background options are a subdued color and are unresponsive. He's dealing with a constant blue background. I think he got a virus but would like to ask you all out there if there is a fix for this.