Removing SpiderSearch.com

One of my users managed to get onto his Win2K box, a SpiderSearch toolbar. The big problem is when you open IE6, it then launches several pop-ups for pornographic sites.
I spent several hours deleting cookies and history, removing registry entries, and updating IE. Nothing seems to work.
It will pop up independent of the user.
Short of toasting the machine, has any one had any luck in getting rid of this?
(User is either not saying how it got there or “Doesn’t Know”)
Any help would be appreciated. This machine is scheduled to be re-formatted next week. (User is locked out until afterwards.)

Thanks