I just installed a Sapphire Radeon HD 3GB 7950 into my computer using Asus P8Z77-V LK motherboard. It wont detect the video card anywhere, I tried to find it in the Device Manager and it doesn't show up, I tried to install the AMD Flash Catalyst, but the install wont work and will not install any programs. I am using Windows 8. when I try to plug in the HDMI into the GPU it wont work, and I have tried to set the GPU as the primary graphics and it goes straight back into integrated when I reboot. Any help please.