Step 1

Identify your card, you can usually do so by right clicking on your desktop and selecting properties then advanced, as seen in the video.
Alternatively one may go to Device Manager via Start - Run - "devmgmt.msc"
Once there, click the + next to Display adapters.

Note: If you have an integrated card this means that the your computer is using part of its memory to serve for graphics processing. If this is the case you do not actually have a videocard and therefore the drivers cannot be updated.

Step 2

Now that you have the name, your best bet is to go to the company website, may it be ATI, NVidia, Vodoo etc.

Step 3

On the main page of the site scan for Downloads and/or Drivers.

Step 4

Now you will be asked to identify your card. Select your Operating System, card series (fancy name they put on the card such as Radeon,Geforce etc) and finally the number, then browse the results for the latest date and download.