Here is your site for HP approved driver upgrades. It may not be the most up to date, so once you know exactly what hardware you have you may want to look for the manufacturers website to see if their is a newer driver than on this site:
http://h10025.www1.hp.com/ewfrf/wc/s...461443&lang=en
It even has a bios update on there, so you can try that!
If you don't know how to, then post back and I am sure I or some one else will be able to walk you through it.
You might also want to check out the ATI forums, as others may have that issue. It may even be that your card is damaged.
What card did you have before and did it do the same thing?
crabby