I am running Windows 7 x64 and have NOT been able to get the audio working at all. I can plug in my USB headset with no problem. When I go into the Device Manager there are two warnings under sound controllers: ATI High Definition Audio Device and High Definition Audio Device. I've updated the BIOS, moved the 5850 to a different slot, and tried installing older drivers for the Realtek controller. Nothing I do seems to help! Yes, the HD Audio is enabled in the BIOS settings. Is this a conflict between the video card and the mobo?
I should clarify that the 5850 has an HD Audio controller in it. The error for both of these devices is "Windows cannot verify the digital signature for the drivers required for this device. A recent hardware or software change might have installed a file that is signed incorrectly or damaged, or that might be malicious software from an unknown source. (Code 52)" I know that I have the right drivers and supposedly the mobo is "Win7 ready".