grimx133

First thing to do is to try going into your bios and see if there is a setting for disabling the onboard video, or setting the priority to pci. Being an oem bios, doubt there'll be many options. Mostly, onboard disables automatically when a video card is present, but there are some where it has to be disabled. So, if there's nothing to disable onboard, or set pci graphics as the primary boot device, then try the driver install.

Hook up to the old, with the new card not in the slot, and go to device manager and under display adapter, expand it with the + sign and then right click on the onboard video adapter showing and select uninstall. Then shut down the computer. Now you install the new card and then when you turn on your machine tap F8 to select the type of boot. Highlight vga mode in the list and boot your computer up. Vga mode loads the standard vga drivers that are included in xp and not any card specific drivers. Then you install the new drivers and reboot into normal mode.

Should always uninstall the old and then install the new from vga mode or safe mode if that isn't available.

Just one other thought right now. PCI slots can be a little finicky about which slot you select for a device. Try the slot closest to the cpu first which is closest to the middle of the motherboard, not near the bottom edge. I couldn't find anything on specific pci slot, but, they it's a possibility.