For graphics card drivers: Right-click anywhere on your desktop, hit Properties, go to the Settings tab, and see what graphics card you have under 'Display'. If it's Nvidia, head over to
www.nvidia.com and navigate to the "Download Drivers" link, choosing the correct and most recent one for your type of card. If it's ATI, your source of drivers is
www.ati.com, and you need the "Drivers & Software" link. If it's anything else, use Google to find your manufacturer and download the most recent drivers.