From what you've told me, you have not done 'that'. Look up your GPU manufacturer, be it Intel, Nvidia, or ATI, go to their site, and download the appropriate driver directly from them. I'm assuming you know how to properly install a driver over an older one - if you need help, ask.
There are some programs that you can download that will find drivers for you, but I've never found any that were less advertising than they were helpful. I don't recommend them.