"We couldn't complete the updates. Undoing Changes"

This is related to another issue that I posted about (still unresolved, related to installing 22H2) but the following is more clearly defined because it's being caused by a single earlier update. So a new thread seemed like a good idea.

A PC I'm trying to update is one that I rarely use and it isn't even connected to the Internet that often.

It's running Windows 10 Pro, 64-Bit - Version 1909 (OS Build 18363.1556)

As you can see it's running a pretty old version that's now unsupported.

A couple of years ago it failed to install one of the updates, specifically KB5003635

It kept trying and I got so fed up with it that I installed Shutup10 to prevent the frequent update attempts, this also had the benefit of enhancing some privacy on the PC, etc. I should point out that this problem weren't caused by Shutup10 as it happened before it was installed.

Since then I've reset Shutup10 to the Windows default values and don't use it any more.

I've tried manually installing KB5003635 from the Microsoft Catalog page (https://www.catalog.update.microsoft...px?q=KB5003635) and it appears to go through the process but then after the reboot it's installing away quite happily and gets into the high percentile then gives the error:

We couldn't complete the updates. Undoing Changes.

As an experiment I've tried installing other updates after KB5003635 but none work.

I've tried disabling the virus checker too, but no luck.

I feel that if I could get KB5003635 installed then all may be well with the rest of the updates, but how to install it?

It would help of course if I knew WHY Windows was failing to install the update but it's not that helpful.

Tempted to reinstall from scratch but as mentioned earlier I have so much installed on the PC that even though I don't use it much I use it enough for it to be a huge pain to reinstall everything.

Note that there is an update prior to KB5003635, and that's KB5003212 which is a Preview build which I've never tried to install (I don't install preview builds if I can help it).

Thanks a bunch, I'll give that a try.

Edit: no luck with that TechBench site I'm afraid, if I select the required version it errors with:

"File is not available for download"

I can find it elsewhere but which other sites can I trust?

The TechBench site does point to:

Home :: List of files by Microsoft(R)

It does though only have the files available via torrents and trying to download generates many 'compromised' errors by Malwarebytes.

Thanks, just tried the Windows ISO Downloader that Option 5 in the tutorial points to and it has a version 2004 for May 2020. However, my currently installed Windows 10 version on the old PC is Version 1909 (OS Build 18363.1556) which, according to MS's site, was released on May 11 2021.

Now I'm wondering this: why is version 2004 dated as May 2020 while my installed version 1909 is dated as May 11 2021 ? This is puzzling me.

Ah, I see. I've learned something, thanks. :)