something is seriously not right with your pc then, more than likely not the fault of the pc but windows, you may need to look at the back of your pc and find out where your graphics card is situated, if its near to where you plug in your keyboard/mouse/usb/audio, then its an onboard model, if its connection point is located in a horizontal slot towards the bottom of the pc, expansion bay slots, away from the keyboard / usb / mouse/ etc, then its an expansion card
if its an expansion card its just a case of opening the case and finding out what make of board it is, likely to be ATi or nvidia, then u need to go to the card makers website and get the latest drivers
if its an onboard solution, your best bet is to try and identify the motherboard make/model number and get the relevant drivers for it, if this is the case, sisoft sandra is a hardware interrogation tool, looks a little complicated if your not used to it but it is good for getting the right data you need
if you need any help get back to me