Latitude 5400, no sound after May 2021 Windows update

WIndows audio service was a red herring, I noticed on a machine that the audio service is started but the speakers/mic are still in an error state until we visit the ease of access screen, or until we add localservice to local admins. I have 600 machines blocked from picking up update 2004 until I have a fix for this

We've found a few machines which haven't picked up 2004 (still on 1909) which have the issue. The only update they've picked up is the one mentioned in the original post, "2021-05 Cumulative Update for Windows 10 Version 1909 for x64-based Systems (KB5003169)".

We've had the same problem with a number of 5400's.

What we've found that seems to work is to apply the latest BIOS to the machine, then run a system restore and jump back to before the updates were applied. Sound should be back.

So far (knock on wood) that's solved the issue and the update can be applied again without breaking audio.

But boy a fix sure would be nice wouldn't it?

It appears that monthly patch that failed was causing the following registry key to break.

consolesecurity located in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations
The ConsoleSecurity shows as Zero-Length Binary Value

Import the registry key from a working machine (which is the same for all machines I believe) and this has fixed the issue for me.

Todd, congratulations sir I believe you've found the final, and more appropriate solution than the net local group modification.  After seeing your post, I checked one of our affected computers, and sure enough the registry value was empty.  My assumption is the May cumulative updates corrupted this somehow and there's nothing putting it back yet.

I'm curious if you'd be willing to share how you identified this as I spent more time trying to figure it out than I care to share, and it's a bit odd for a terminal service configuration to have an impact when not using remote desktop.  However, conceptually it does lend itself towards some behavior we noticed with a few other workarounds that would break as soon as the user logged off and logged back in.

For anyone worried about copying some scary looking binary values from one computer to another, I converted the binary data to a more human readable SDDL security descriptor format.  The output from a default Windows 10 machine is below, and it looks pretty straightforward without any additional unique SIDs that you might find from domain or locally unique groups on the PC.  Importing the reg value from any other Windows 10 computer should be safe on most computers.

"O:SYG:SYD:(A;;CC;;;IU)(A;;0xf03bf;;;SY)(A;;CCSWLOSDRCWDWO;;;LS)(A;;CCLO;;;NS)(A;;0xf03bf;;;BA)(A;;CCWPCR;;;RD)S:NO_ACCESS_CONTROL"

Going to give this a try and report back. If it works I will owe you 600 beers Todd - one for each affected machine!

                I was waiting to see if Junes patching would also fail in some cases and break users machines here is what I know.

• The issue only occurs with patch KB5003169
• Not everyone is affected only users who experience the following: Patch installs but fails, and retries 2-3 times. After it is installed users have the following issues.
• • Issue #1: Have No Audio (Red X)
  • Issue #2: Users now have use Ctrl Alt Del at log on 
• This affected multiple companies as seen here for Microsoft or here for Dell.

Solutions Shown Below. 

ISSUE #1. It appears that monthly patch that failed was causing the follow registry key to break.

consolesecurity located in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations

The ConsoleSecurity shows as Zero-Length Binary Value

However, it should appear as

Import the registry key (from known working machine, I have regkey if needed) to affected user to resolve this issue. 

ISSUE #2 - All users that have this issue also have another issue where they are required to use CTRL ALT DEL to log in

This is related to Local Security Policy being changed

Users were changed to

Changing this to enabled fixes it

Thank you @Todd LaRiviere
This worked for me and is more secure that the other CMD fix.

Solutions Shown Below. 

ISSUE #1. It appears that monthly patch that failed was causing the follow registry key to break.

consolesecurity located in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations

The ConsoleSecurity shows as Zero-Length Binary Value
Exported the registry key from known working machine, saved as a reg file the ran on the affected laptop to resolve this issue. 

Dude, after almost two years I was finally able to get working sound without workarounds.

I've created the account to say THANK YOU @Todd LaRiviere 

There are a lot of people struggling with the same issue, I'll try to spread your amazing solution.

Hello! I really need this! But my customer has only 1 dell latitude of this model.

Do you have the registry key to share? Pleaaasee

Hey Todd, after 1.5years I found your fix finally working. Thank you very much. You are correct about the fix creating this issue in Windows ever since May 2021. I had a Intel NUC PC which stopped working as well for all these years and my workaround was to restart the Windows Audio endpoint service and click on Ease of Access every time i restarted the machine to get my sound to work. Finally your Registry fix made it work. You deserve a kudo.