If you haven't added on any video card, then I Assume you still have your onboard chipset. Which would be a GeForce 6150LE.
To update your drivers, just go to (http://www.nvidia.com/Download/index.aspx?lang=en-us). Then put in your GeForce 6 Series. Then your Operating system (Vista, XP, etc). Then download. There ya go.
However, if you added a video card then I can't help you unless you name the card you've added.
