|Brajesh, try downloading a program to monitor your system temperatures, like HWMonitor. Post your temperatures for your graphics card when you turn on your computer, when you browse the internet, and then when you game (do it before it turns off). |
If your temps are too hot, try cleaning out the dust inside the laptop by removing the back cover. It definitely sounds like an overheated graphics card. In your case, its a few years old and was pretty cheap then (the 8800 gt). It might be time to think about upgrading if you plan to continue gaming.