I disabled anti-aliasing in catalyst control center and now FF7 starts and i can play, but when i close it, i get a blue-screen

But i dont get the bluescreen everytime i close ist, only sometimes...
EDIT: I made some settings in ffdshow and since that i haven't got any bluescreen or black screen so i think this problem is solved. Thanks for all help!
EDIT2: OK, the problem is not really solved: I can play FF7 without FSAA and AF but when i enable it and start FF7, i get a weird black screen with vertical wave-formed shapes, when i exit FF7 (with ALT+F4), i get a blue screen and my Computer reboots. But i dont know why that is because i used to play FF7 with FSAA and have never had this problem...