You didn't say much about the problems, (eg partially installed, why?), but that is probably why the uninstall and Add/Remove programs wouldn't uninstall it.
The only other way is manually. Use Windows Explorer or My Computer to search for the folders and files where it was installed to, typically the games program files in the sub-folder "Program Files/{whatever program folder name it is}", and delete that folder, and possibly your "Documents and Settings" folder for your username and delete the game folder there.
Then you get to hunt down any shortcuts on your desktop and in your Start Menu and delete those.
There may be other files elsewhere in the system, usually in C:\Windows\System32 folder, but you are not likely to be able to find those, so there's no point looking.
Then use a recognised registry cleaner to seek out any orphan registry entries and delete those.
Mark
I have Windows XP Home Edition = SP2 with 2.66 CPU & 512 memory.
I have copy of a game partially installed and would like to un-install it completely.
I tried everything from "Add/Remove Programs" to the game "Uninstall" folder...Nothing works and it is taking a lot of space on my PC.
Please advise on alternatives to get rid of this gamne altogether off my PC.
Thanks so much for the help.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic