I recently had a similar problem with a coworker that was seriously hijacked on her laptop by a music site that she had visited. I noticed her system was always poping up with IE pages and loading search bars and banners on the network. I finally was able to get it all cleared up by using a combination of Zone Alarm, XP task manager and Ad-aware. I found these three to be really usefull as ad-aware would clear out the spyware, then when I rebooted, zonealarm would show me what applications were trying to access the net, and I was able to disable them through task manager, physically delete them, then run adaware, zone, task, and keep the process going till I was finally able to eliminate it all from her system.

Just a suggestion.