Sorry to maybe offend u in any way Spek.... but in the Bios, under Advanced / Chipset Configuration / if you scroll down there is not an option for HD Audio? Or is it greyed out? According to the Bios Screen i saw HD Audio should be between Inte(R) Ethernet Connection I219-V and Front Panel categories in the Bios. <S> man hope u get it running .
38 beat me to it, as I had to download the Motherboard manual and read it, but as 38maw posted, switch from EZ Mode to Advanced Mode when you enter your BIOS settings to allow access to all the Advanced settings
I have also found that the ERROR CODE: 0x000000FF , can be caused by any number of different things conflicting with the OS Installation and Audio Devices and / or Drivers that might be loaded ( example: HD Audio Driver on your Video Card )
Here is another link that is similar to the one 100Coogn post or trying to resolve the error:
https://appuals.com/how-to-fix-install-realtek-hd-audio-driver-failure/This ERRORCODE has been in the Windows family ever since WindowsXP if not before, and sometimes comes up from a corrupted File in the Operating System ( OS ) installation or it could possibly be a corrupted OS Installation
Removing all Audio Drivers and removing or disabling all audio devices from the system manager then doing a reboot, then let Windows load it's default Audio Driver if possible
then update the Audio Driver with the correct RealTek HD Audio Driver ------> ASRock Z170M Pro4S Realtek Audio Driver 6.0.1.7543
Good Luck and hope you get it figured out Spek!
TC
EDIT: there is a longshot chance that the onboard RealTek Audio might possibly have gotten grounded out or could possibly be "Dead", which will also cause this ERROR CODE to pop up.... I truly hope this is not the case