http://www.finalfantasy7pc.com/mods/aalis-custom-graphics-driver/
you basically need that, and to do a few other modifications, 8 works pretty well with it, but for 7 you need to download the input.cfg and a save file and to create the structure manually to get it to work.
There's some other cool tools available on this site:
http://qhimm.com/
for those of you who are nerdy enough to have the original and too cheap to repurchase it. (Yes I know, steam finally put 8 up...)