I got exactly the same problem here The computer don't work after some time viewing Video and its even worst with DVd playback (cant watch more than 20 minutes) The problem seems to be an overheating from the Graphical chipset (ie Intel for me not NVIDIA) The processor doesn't overheat (45-50°c with SpeedFan), when video playback it doesn't use more than 40% UC but when the overheat occurs It peak to 100% and the taskmanager doesn't show any anormality The heat come from the chipset