Computer freezes with random lines

[panparade]

I recently built this new pc and it freezes when i run firefox(in 5-10 mins) or some other browser(1-2 hours) or when im playing warcraft 3.

proc: core i5-2500k
ram: corsair vengeance 1600mhz 8gb (4x2)
gfx: xfx radeon 6790
mobo: asus p8z68-v pro

First it used to run vpu recover and stop my pc again and again, then i replaced my gfx card and now it freezes on the applications i mentioned with vertical colorful striped lines(screen goes yellow on firefox and striped lines on others). Is this a video card problem or can this be related to ram?

edit: it only stops on these applications, i've played heavy games such as witcher 2 and starcraft 2 for hours, never froze on them.

and my psu is of antec and its 850W

 

[pro-gamer]

i think its a issue with display driver download new one and latest.