Windows Server 2016 Essentials Updates failing due to bloated registry?

[zerod]

Hello, I've been struggling with getting Server 2016 updates to install for the past few months with various errors from both the Windows Update GUI and offline installers from Microsoft Catalog.
Windows Update error codes: 0x800706BB, 0x80070020, 0x800705b4, 0x800705aa
Clearing the updates cache did not help.

I've run SFC /scannow which comes clean but when I try to run DISM repairs, the commands time out with "insufficient system resources" despite CPU/RAM under 50% usage.
OS drive also has plenty of space.
The server does not have a "RegistrySizeLimit" registry key set.

In my investigation, I've discovered that the COMPONENTS registry hive file is over 2GB, which I've read is the max size it can be.
I've run RU on a copy of the hive file:

I've attempted to compress the bloated registry via Microsoft's instructions, but it did not seem to shrink the size: Compress large registry hives - Windows Server

I've attached the CBS logs from last night but I'm unable to run ComponentsScanner due to an exception:



Am I on the correct train of thought with the registry being the issue, or is it something else?
Any help is appreciated. Thanks.

 

[x BlueRobot]

It does seem that your hive has grown far too large; the maximum size is around 2GB. There's two options which I can think of: delete any unused keys - this will very difficult to determine manually - or attempt to use:

DISM /Online /Cleanup-Image /StartComponentCleanup /ResetBase

I would create a backup before running the command though.

 

[zerod]

Thanks, I was wondering about that command but wasn't sure if it cleaned the registry or just the files.
I'll give that a try over the weekend.

 

[x BlueRobot]

Okay, please let me know the result when it is done.

 

[zerod]

The command stopped after a few hours with "insufficient system resources".