Good news! On a stroke of inspiration, I remembered the DVI-to-D-Sub adaptor the video card brought, used it, and booted up fine with my 6800GT without any artifacts! I also managed to install the Force Ware drivers without any problems! Note: I still have the integrated video drivers installed, though there doesn't seem to be any conflicts. I changed the "Primary Graphics" to AGP in the BIOS. Well, I'm installing HL2 right now and I'm gonna go try it out.