I have a ROG Maximus Z790 Extreme motherboard running BIOS version 0904.
I've purchased and installed a new sound card which has solved a number of issues that I was having with the onboard audio.
Unfortunately, every time I restart Windows, the default audio device changes back to the Realtek controller, and ignores my preference for making the sound card the default.
I want to disable onboard audio in BIOS but have found that the option to turn off HD audio (which should be under Onboard Devices) is not there at all.
How do I completely disable my motherboards onboard audio controller?