Drivers
How to find a driver
If the hardware is built into the motherboard, reboot the computer and write down the motherboard model number that comes up on the splash screen. You may need to reboot a couple times to get the whole number written down. Once you have the model number you can go to the website of the motherboard manufacture and download the driver.
If the card is stand alone, open the computer and write down the model number from the sticker on the card. Google the model number which should lead you to the brand of the card. When you know the brand of the card you can go to the manufacture's website and download the driver.