Windows 10: Updating from 1903 to 21H1 failing

I'm currently on build 1903 and from my understanding, support for this has been pulled since some day of December 2020. I currently have two updates "pending" from Windows Update:- Feature update to Windows 10, version 20H2 - Error 0x80070002 which afaik is outdated as the latest build is 21H1- 2021-05 Update for Windows 10 Version 1903 for x64-based Systems KB4023057 - Error 0x80070002 which I can't even find on the Microsoft Update Catalog to update manually as 1903 has been culledI've done a lot of Googling and browsing Microsoft threads to try and fix this. I've used the Media Creat

:)

 

Windows 10 fails to update


When you finish testing the Avast suggestion, make sure that you restart your machine.

Then if the issue persists, please return to the trouble shooting list in post# 89

I think there are three steps that remain; the WU troubleshooter, reset WU components, and manual WU reset.

 

KB4025339 Fails Install 0x80070564

Thanks
I am trying Eagle 51's suggestions now. Windows Update troubleshooter found a bunch of errors and fixed all but one.The update is trying to download KB4025339 again. I'll see what happens. At step one troubleshooter finishes with one error unresolved "Potential Windows Update Database Error Detected-Not Fixed". Windows update stalled at 0%.

At step 2 same troubleshooter error. The KB finished a new download failed to install.
Did step 3 KB has downloaded but fails to install.

If Eagle's suggestion doesn't work I'll try EdTittel's suggestion

Tried bothe Eagle & Ed 's suggestions - do not work. Anyone else?

I have noticed that the latest update for my nvidia drivers has failed to update. Wondering about that!

 

Cannot update to 1903

O_O thats a lot of steps. Starting in a few mins. Quick question though:
You list a set of instructions for "Windows 10 iso as an in place upgrade repair" with links, and then you included a box for "Routine troubleshooting steps" with 13 steps including links.

Which should I be following first?

PLEASE don't hate me for asking this as this just occurred to me. Should I try the update in Safe mode? I downloaded the MediaCreationTool 1903, but it wasn't successful in doing the update, nor was it successful in creating Usb install.