The graphics card driver, right click my computer, go to proporties, click the hardware tab, click the device manager tab, go to display adapters, right click what ever card you have(the 7900gs or 7900 gtx), select properties, and then click the driver tab, then make your choice from below....
The next part is up to you, you can either try to roll back the driver or you can do what I would do and go to
www.dell.com and find the newest driver for your card and download it to your desktop. Follow the process I spelled out in the last paragraph and uninstall the old driver completly, restart the system, and when its restarted click the file you downloaded to your desktop and follow the instructions to install the new one.
sorry I have to go and wish I could type a little more to explain rolling back the driver but my battary is about to completly die. I would do the complete uninstall and reinstall any way its would work better in the end and you would be able to ensure that you have the newest driver correctly installed.
Chad