With previous versions of Windows, the "Tweak UI" had the ability to rename and remove entries from the add/remove program menu. However, the XP version no longer has this option.

Aside from manually editing the registry, you can download a 3rd party uninstaller, like these.
Most of them are full-featured trial versions which will give you the option of removing the listing if the uninstall fails. As an added bonus, several of them even scan your computer for junk files and old registry keys. They all ranked pretty well, with the interfaces being the most common complaint...you may want to check out the screen shots to determine which one is right for you.

Hope this helps,
John