There wouldn't be any harm in deleting it all yourself.
Just delete the ff7 folder. Then, for completists sake, go into your registry (hit start, and RUN. Type "regedit" in the box) and delete ff7's registry key. It's under HKEY Local machine - software - Squarestoft, inc. - ffvii.
Do that and you'll be fine =) In fact, you can probably get away with not doing the registry thing. Dun worry about it too much.