Problem with graphics in games

I have a problem with the graphics in some games, i don’t know why it’s happening but i have a theory..
It started when i switched the graphics adaptor (or something) from DirectX to OpenGL in a game, i think it was Gish. After that the graphics started acting weird in lots of games, strangely enough all of the games which it acted weirdly in is 2D games..
Example:

(Main menu in Acquaria if you were wondering (atleast i think it’s the main menu))
Anyone have a solution? Or do i HAVE to format my PC just to fix it >.<
Answer #1
Try updating your video driver mate. See if it helps. Good luck ^_^
Answer #2
Done that numerous times..
Tried uninstalling drivers and downgrading, tried using beta drivers.. Nothing helps..
(Nvidia 6600 btw)