windows stopped working!

Hello,

everytime after I finished playing a video game in my PC, a pop window says, windows stopped working (with a black screen), then looking for solution and then, "window is restarting" and the desktop comes back to life. and everything runs normal, the whole thing takes like 30 sec. but i know it's not normal..

it has an upgraded video card, and the specs fit my video games, so I don't know what could it be?

help please...