Windows 10 update not working - partial update then undoes changes

Microsoft Windows 10 Pro Version 20H2 - build 19042 - 500gb Sata SSD - 16GB RAM

Downloading Update: 2020-11 Cumulative Update for Windows 10 Version 20H2 for x64-based Systems Windows
Update: Error encountered. "Some update files are missing or have problems......

If I click Retry it will download 100% and ask for Re-Start.

Press Re-Start and it will begin to update until it gets to 30% then it will restart.
It will then continue to install up to 48% then restart again.

Then says "we couldn't complete the updates and are undoing changes"

It does this three times (three re-starts) before finally loading Windows as normal.

I have tried many of the suggestions found online mostly from a CMD point. Tried several re-sets for Windows Update but nothing has worked so far. net start bits - net start wuauserv - net start appidsvc - net start cryptsvc etc.... Have just run BAT file from this forum too, no change.

Would be most grateful for help with this.

Thank you.

You'll probably be talking to the right people if you read then post in
KB4586781 CU Windows 10 v2004 build 19041.630 and v20H2 19042.630 - TenForums

Denis

Mike,

Thanks for the Rep. In answer to your question, just go to that tutorial and you'll see at the bottom of the page [any of its pages] that it has a reply box just like this thread does.

The post gets added to the end of the tutorial thread whichever page you were on when you typed in the reply box.

Or have I misunderstood your question?

Denis

Mike,

If you read the tutorial that I linked to in my post #2, you can read it through / search it for your problem then post in it. That thread is seen by people who have experience of this particular update so some of them might have encountered and overcome the problem you are having.

That tutorial contains a direct link to the update so you can try again using it directly [rather than letting Windows update download it for you then running it].
- That sometimes works.
- But do note the tutorial reference to an SSU - KB4586864. Download and install that first [if it had already been installed then it will just tell you. No harm will be done by the attempt.]

KB4586864I cannot advise you properly because I am avoiding that Version. I'm still on Version 1909.

Denis