There is an uninstall method availiable, and it works on 2k and XP. However I must warn you, the MMC (Computer Managment) things require IE, and won't work without it.
Also, a 2k system must be pre-SP2 and XP must not have SP1 installed AND they must have system file protection disabled so the files aren't replaced right away.
http://www.webattack.com/get/ieradicator.shtml
It says only for 98/ME, but I've used it on 2k/XP. However, as I say, some things won't work if you remove it.