VGA is the default device windows installs, you need to find out what the graphics chip/card is on your pc then install the drivers.
if you have internet access you can download everest home edition and it should tell you what the graphics chip is, then you can make a best guess of where to get the drivers.
if your still not sure, just reply here with your machines model and we should be able to find it for you.
Matty Gilbert, January 2009