In order to uninstall the game from your computer, I suggest you use Revo Uninstaller. Even if it can't uninstall the application normally, it will force it to uninstall by wiping out all traces of its presence from the system.
Also, you can remove it manually. Go to (C:) > Program Files > EA Games > Medal Of Honor Allied Assault and delete the game folder. After that, go to Start, type regedit and open the utility. Navigate to HKEY-LOCAL-MACHINE > Software > Microsoft > Windows > CurrentVersion > Uninstall and delete {823A68CC-3049-4A6B-8F63-7DC85E4BB1C9} and {0DEA94ED-915A-4834-A87E-388D012C8E02} folders.
