whenever i play game sometimes my screen freeze and gets blurry and some small green + blue + red line on the screen however some games like CoD 4 and GTA SA rarely get this error but games like Sims 2 Assassins creed get this error frequently.Most game force me to reset my pc but some like sims 2 reset it by itself.i'll try to post some screenies later.i've also try scanning for artifacts in ATItool no problem.
EDIT:FIXED IT.some moron thats has been overclocking the graphics card forgot to return it to the default clock