I have a DELL Optiplex GX240 pc, the one that looks like a brifecase. It has an ATI rage 128 pro ultra agp gl 4x card but I wanted a 3d card so I have an a ATI 3d rage pro turbo agp but the pc is a low profile system so the card would not match up to the agp slot. so i bought a card for pci but the monitor will not show, so how do you disable a agp slot so the pci will run instead?
You need to insert your old graphics card, go to BIOS. Then search for something called "graphics port", and set it to PCI instead of AGP. When you did that, hit F10 to save it. Your screen should go black. Then wait around 5 seconds and turn the PC off using the power button.
Then, take out your old graphics card and insert your new graphics card and hook up the monitor to one of its graphics ports. Boot up the system.