I can't uninstall itunes!!!!!!! (Windows XP)

When I try to uninstall itunes from the control panel I get an error mesage: "The feature you are trying to use is on a network resource that is unavailable....". I checked all around the internet & I was directed to Microsoft Fixit to help uninstall programs. So I download that, but get a new error message that says "Troubleshooting cannot continue because an error has occurred." I asks if I want to download a utility to fix that - a file called Diag_mats_network_global.Diagcab. But when I try to run it my computer says there is no program to open the file. I have Windows service pack 3, WIndows installer version 4.5....HELP!!!!! Microsoft support wants $99 to help figure out why their Fixit won't work.