Okay my computer has no virus ( checked with Avast ) and its all fine. But when i watch youtube, play flash games, or a game like maplestory. It plays fine and than the screen freezes. the desktop is still on but the screen is dead. * i have a mac monitor. I have a good graphic card, so i think thats fine. but after my computer freezes i half to shut it down. After that when i turn it on the screens black. so i need to keep turning it on and off. till soon when i turn it on for 3 sec it shuts down. so it auto shuts off! and i need to wait like 2 hrs before i can turn it on... PLEASE HELP I WANT TO PLAY COD 4 with my nvidia geforce 9800 gt.