Actually, the Intel 945G Express Chipset is based on PCI Express technology. If you have added a PCI Express video card, there is no need to disable the onboard graphics. This should be electronically disabled by now.
On the other hand, if you have added a regular PCI video card, I am afraid there are no settings to disable the onboard graphics controller. You just need to select at BIOS level the output device. Consult with your computer manufacturer for video settings in BIOS.
Hi Allen, Thank you for the answer, this will sure help with future upgrades. I did install a PCI E card and as I said before the card is working just fine. I did remember from years past that it may be necessary to disable the on board, but, since it was working I just needed to ask to be sure. Thank you again for the quick response. Dale