I had been running Windows 7 64 bit since I bought Gigabyte 990FXA UD5. I had no trouble with this board and it was running flawlessly in Windows 7.
Two days ago I installed Windows 8 Pro with Media Center 64 bit edition. Windows 8 generic drivers were working with all my hardware components. But as we know Dolby Home Theater is not available with generic driver, and to get this we need to download and install driver either from motherboard vendor's website (Gigabyte) or from the Audio Chip vendor's website (Realtek). I downloaded latest audio driver from both websites for Windows 8 64 bit. Audio Driver version from both Gigabyte and Realtek is same and latest (r2.70)
Firstly I installed the one from Gigabyte, everything seemed fine and installation was successful, I restarted OS and I did find Dolby Home Theater V4 icon in my Taskbar list and in Windows Control Panel as well. But when I play any song/video/DVD, Dolby Home Theater is not working even if the Dolby Home Theater power button is switched ON. I am getting standard sound compared to what I had been listening in Windows 7. I mean software loads without any hassle or compatibility issue, DHT software is opening without any problem, but the main problem is that it doesn't look to be working anymore. When I played sounds in Windows 7, DHT Graphic Equalizer was working and showing that you were getting Dolby effects but now in Windows 8 that effects are no more and Graphic Equalizer remains silent all the time. Please help me I've tested it with both drivers but its not functioning.
One more thing I am not getting virtualized multichannel sound effects (5.1/7.1) from the front panel green colored audio jack. For example If I set 5.1 channel in Realtek Sound Manager and play games like Battlefield 3 online, I am only getting sound effects of front set of speakers. I hear sound from left and front right in Realtek Sound Manager sound test but I get no sound from other remaining audio channels. All this had been working with Windows 7 and a Headphone without any problem.
Please help
I've installed all latest drivers for all motherboard components, I have also installed latest BIOS ver F12a (I've tested with some old BIOS versions too in Windows 8, but it didn't work).
My system configuration:
# Gigabyte 990FXA UD5 Revision 1.0 with BIOS f12a
# AMD Phenom II X6 1055T at default clock
# ADATA 2 x 4GB DDR3 1333 MHz CL 9
# XFX Radeon HD 5770 reference design
# 2 x 500GB Seagate Barracuda 7200.12 in Raid 0
# Corsair TX850 V2
# Microsoft General keyboard and Mouse
# 18.5" Acer V193HQV LCD Monitor
Many thanks to all experts, please don't ignore