It is not overclocked, as I said, I just remove the forceware drivers, remove my fx5200 and put the 6600 card. This is my first time I put a video card whitout installing fresh windows. I didnt overclocked, the fan is spinning, I dont know what is Ocing. I use a 500W omega PSU, the +12v has 23A. I am using an Asus a7v600x socket a motherboard.
What do you mean "weird freezes" ?
It can be anything.
Start to check the VGA card.
Is it overheated ? Does the fan spinning ? did you OCing ?
Provide your PC specs.