Hi!
I also have this issue now, this happened after the 06-2021 cumulative update to 20H2 (the original 20H2 was fine).Pre-history:
Actually, I couldn't boot correctly with 06-2021. It would show my desktop, with icons, but none of my auto startup applications launched, and either WDM or Explorer (or both) were hanging.
Mousing over the Task Bar displayed the waiting cursor, and any number of things, including clicking the task bar, resulted in a dark gray screen (my color scheme), which would then not react to anything. I could still move the mouse.
I could not bring up Task Manager or Process Hacker (not from the CTRL-ALT-ESC screen, not from the task bar (as that would trigger the gray screen)), launch an explorer window or RUN prompt (WIN-R).
So I chose "Uninstall last quality update" from the recovery options. This seemed to work at first, but after restarting again (Windows seemed to still need to complete the configurations), the sound was gone.
Same symptoms.
- Audio devices and Sound devices show up in Device Manager
- All devices report that they're "working properly"
- But Windows says it can't find any audio output devices in various places (volume icon, modern "sound" settings)
- The outputs (or inputs, for that matter) don't show up in the Playback/Recording tabs in the CPL window
- DxDiag tells me "No sound card was found"
I can confirm that this is a software issue:
I restored a disk image I made before updating to 20H2 and the sound was working fine.
I'm still very interested in getting this to work without having to use the month old image, though.
I've tried:
- Deactivating/reactivating sound devices in Device Manager
- Using the troubleshooter for sound problems
- Uninstalling and removing drivers in Device Manager
- Installing generic drivers in in Device Manager, trying to update in Device Manager/windows Update
- Manually adding a generic sound device/drivers in Device Manager
- Manually installing the original drivers from the manufacturer's site
- Displaying hidden items in Device Manager (in case any critical components were disabled and hidden somehow)
- Changing the "UpperFilters" key in Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e96c-e325-11ce-bfc1-08002be10318} to an empty string from "ksthunk"
- Checking system integrity/auto repairing with SFC /SCANNOW
- Checking system integrity/auto repairing with DISM /Online /Cleanup-Image /RestoreHealth
- Plugging in USB soundcards
- Making sure that the Windows Audio service (and Windows Audio Endpoint Builder) are enabled and running
And probably some other things I can't think of at the moment, will add as I think of them.
FWIW, the integrated sound card in question is a Realtek High Definition Audio chipset reporting as HDAUDIO\FUNC_01&VEN_10EC&DEV_0900&SUBSYS_1462D693&REV_1000
But I doubt that that has very much to do with it, as the generic external USB soundcard and the NVIDIA HD Audio device also don't show up outside of Device Manager.
If anybody has any more ideas, let us know!
Thank you all for your time and help! :)