I tried all of the instructions above, they did not work for me howerer, I have an HP with a 32MB NVIDIA GForce 2 onboard video Card, i added a 16MB ATI Video card in my PCI slot, then i plugged in both monitors. When i booted up into Windows XP The 16MB ATI video card took over my onboard video, and i did not have a picture on both monitors. I thought maybe i had to reboot, so i rebooted and the picture then switched to my onboard 32MB NVIDIA GForce 2, i do not know what is wrong, please help me. (Upon first startup XP automatically installed my 16MB ATI Video Card