Just got an hd 7990, and it gives me a black screen as soon as the windows loading screen should pop up, same result in safe mode, and even on a clean windows install. Windows still seems to boot up fine in the background. Works with other video card, and as long as the hd7990 is in my 2nd pci-e slot, it seems to work, I just need to use catalyst to clone the display onto the 7990 and swap the cable. However, it will not work after a reboot, even if I disable the other video card before rebooting. Tried the stable and beta drivers. Really at a loss here, especially since it won't work on a new windows setup, it goes black as soon as windows is done copying the files and it should go into that low-res setup gui. Anyone have any ideas?