crash and black screen during gameplay?

I don't know why, but now in middle of my first match, it turned to a black screen, and stay there forever. You won't be able to hear any sound or anything, it's just a black screen, and the only thing is to shut down the computer, and turn it on again. Can anyone help me to solve this problem? I didn't get any bugs since the X-Traps came out, i really like the gameguard better, because it wont give me bug. There are still hackers out there even though there is a new anti-hack system. Contact me soon plz.