So, a few months ago, I got a new video card (9800gt GeForce) and I had to do the regular stuff, uninstall onboard card, set bios to boot PCI-E... But today I turned my computer on and the screen was black. So I plugged the monitor cable into the onboard slot, and it worked...? So I checked bios, and it still said PCI-E, and I downloaded drivers for the 9800, but it still doesn't work. I don't get what happened, so please help! PS: I have Vista.