'''++Isaac Sana++''' bad hard drive or bad video card . Let us know what you mean your computer switches on. If all you get is the power LED and the fan I would check to see if your board actually has power. Connect a mouse to the USB and see if the LED comes on. that way you know that you have at least power to that. Try a different video card and see if your dispaly shows anything. Of course make sure that your monitro works as well.