Cannot Re-install Program

I recently uninstalled Aliens vs Predator 2 to clear up space on my harddrive. But the problem is, it is still on my Add/Remove Programs list. I went to uninstall it, but it says it completed, and that some files were not removed, but can be removed manually in the windows folder. So I couldnt find the files, but I deleted the folder under Program Files, and then ran RegSeeker. It removed the registry items, and it was no longer on the Add/Remove list. I went to re-install it again, but the same message appears, trying to uninstall it. Can any one help me here?

Btw, I am running Windows XP Professional

look for the files in windows search, and delete them from there, if they won't delete, download a copy of "EVIDENCE ELIMINATOR" and remove them with it.