|I would suggest that you go to the ASUS website and get to the downloads page. Enter your motherboard model and download the latest version of the audio driver software they list.|
Then, extract/unzip the file into a folder on your desktop. In Control Panel, Add Remove - uninstall any software that is associated to your audio chipset. Like Realtek stuff.
Once that's removed, run the ASUS setup file that you downloaded and extracted earlier. That 'should' solve your problem.
If not, there is also a help forum on the ASUS web site. It's listed in the Support area. Or someone else here my be able to better help. But I think this will work for you.