I am trying to add a second monitor (for extended display) to the Dell Dimension 3000. The machine only has PCI slots, so I found an ATI Rage 128PRO 32MB PCI Video Card (VGA output). The existing VGA display adapter is onboard. When I install the video card and reboot, the original monitor will display the desktop (Windows XP), but as it eventually finds the new hardware, it invariably loses all picture on both monitors. I have the correct drivers if I could ever get far enough to install them.
The computer has a 250 Watt power supply. Do you think this is insufficient? It is a basic machine with a DVD/CD-RW, a modem, and one hard drive.