hope it's just the searchURL that has been modified but i would advise cleaning out your system first..... using ad-aware/spyware busting programs etc, another way is to use RegCleaner,
software at jv16.orgthis would help u see what's exactly installed in your system for you to remove it manually, or do a automated registry cleaner,... it's a good freeware !
coz you'll never know what else might be in your winxp system ...spywares are hard to trace and erase.... deleting registry entries such as the simple URL default may not work completely.... the thing may just pop up again after reboot!... I had HELL last time with the SHITTY BONZIBUDDY farked up piece of thing from Kazaa