wxjunkie, if your new video card will be the only video card in your system, then you don't need to fiddle around with the Primary Display selection. But if you're running a dual-display system that requires two video cards, the Primary Display selection will determine which video card the boot splash screen will be sent to - if it's set to PCI, it will be displayed at the monitor connected to the PCI card; if it's set to AGP, the boot splash screen will be displayed on the monitor connected to the AGP card.