Black screen

Every time i join a match I get a black screen. (if i wait in the lobby it doesn't happen) I play for a minute or two and it happens. I have to force shut down my computer to get out of it. I'm using a windows 7 64 bit laptop. This started a couple weeks ago. I was hoping it was gonna get fixed in the new patch but it didn't :'(. I already uninstalled the game over 5 times so don't remind me to.. How do I fix this...