ASROCK Z77 Extreme4 audio driver for Windows 8

[scg]

I just upgrade from Windows 7. I installed Windows 8 upgrade, and download the Windows 8 driver from vendor's website. I connect to the speaker. But the error : Audio device is disabled ? I download the audio driver (Realtek chip) from vendor's website, but still no use. Any help ? Thanks
Hardware : Asrock Z77 Extreme4 motherboard, Intel Core i5 3570K CPU, 8GB RAM, OCZ- Agility 3 120GB SSD, Gigabyte 7770 Videocard