Other:
Since it appears to be the Intel audio solution, and most likely a SOFTWARE issue I would also:
1. check DEVICE MANAGER to see if any issues appear (right-click Start-> Device Manager)
2. in Device Manager, try to update the drivers if you find HDMI audio listed
3. if no luck, run CPU Diagnostic (which may not check for anything audio related but worth checking anyway)
https
/downloadcenter.intel.com/download/19792/Intel-Processor-Diagnostic-Tool
4. You can run the Intel Software tool: https

/downloadcenter.intel.com/
5. If nothing detected, you can do something similar to STEP#2. Basically, use "Programs and Features" to remove any Intel software that may be applicable and/or try rolling back or doing driver update checks through Device Manager.
*READ*
Before doing any of these software changes, I suggest creating a RESTORE POINT.
I would also make a backup IMAGE using Acronis True Image or similar once you've got this sorted out.
*ROLLBACK??*
If really stumped, if this was a Windows 10 update there should be the option to RESTORE to the earlier backup. There should be a backup IMAGE stored to do this unless you intentionally removed it using the cleanup tool (i.e. the "OLD" file).
If you can restore the backup, then make sure you have everything you need. I don't think it changes files but it should restore all programs to the way they were. If in doubt you can backup the entire thing to an external USB drive if you have one (if not, I suggest getting one).
OTHER:
I bought myself and my bro-in-law a WDMYCLOUD. It attaches to the ROUTER via an Ethernet cable, so it's available as a read/write device to all computers or media players. I have some shared files, as well as video content that I play on my PC and two media players around the house.