Well you seem to have already looked at the registry. In registry, you normally have 2 keys where you'll find software branches...make sure you look into both (if you haven't done so already).
If you have removed the program from (add/remove) in control panel. You still have 2 places to check.
- In program files (i.e. C:-Program Files-Electronic Arts-game name)
- My documents...the game folder (save it somewhere else if you want to save your games for now at least and delete that folder.
If none of these work or if you have already looked into it then I really don't know