Windows 10: Cum. Update for .NET Framework 3.5 and 4.8 for Win 10 x64 Won't Update

I successfully managed to install 20H2 , version 20H2 (Build 19042.804 but my update history tells me that since 02/09/21:

"Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10 for x64 (KB4601050) failed to install."
On the 'generic' Windows update part of the history it also says:

"There were some problems installing updates, but we'll try again later. If you keep seeing this and want to search the web or contact support for information, this may help: (0x80071a91)"
I've attached some screen shots to clarify.

:)

 

KB4586876 Cumulative Update .NET Framework 3.5, 4.8 Windows 10 Jan. 12 Win Update

Phil,

This might all be pretty confusing now.

I suggest

1 Turn on updates for other MS products - my post #22
2 Run WU to see if it now shows that KB4586876 .Net update as being required

3.1 If WU lists it then install it.
4.1 If it installs and there are no remaining problems, stick the kettle on.

3.2 If WU still does not list it then use that .Net fixer tutorial I gave you a link to - my post #18
4.2 If the problem defies the fixer tool then study the Ghot guidance in that other thread I gave you a link to [ - my post #18] and consider Ghot's suggestion of re-installing the runtime [his post #21].
5.2 If it refuses to install, try reinstalling v3.5 - Install .Net Framework 3.5 - TenForumsTutorials The update is for both 3.5 & 4.8 but I suppose there's a chance that reinstalling 3.5 would give something a kick up the pants enough to get it all working.
6.2 If it still won't play, consider unloading then reloading both .Net entries in CP, P&F, Turn Windows features on & off. We used to do that for WMP in Windows 7 so it is a pretty well-established method but I have not seen anybody apply it to .Net entries before so you might want to discuss it further before doing anything about it.

Best of luck,
Denis

12:29 - I have now finished fiddling with this post.

 

KB4586876 Cumulative Update .NET Framework 3.5, 4.8 Windows 10 Jan. 12 Win Update

Hi Denis:
Thank you for your detailed instructions!! This will probably take several days & I'll keep you updated.

I did steps 1 & 2. This installed more updates than I could count...something like 20-30. However, KB4586876 was not listed. Unfortunately, I had to undo several things (I now remember why I didn't update all MS products). I have Word, Excel, & Access from 2003, as well as Word & Access 2016. Updating MS products caused a "file validation" problem whenver I opened a .doc file. I fixed that (with a registry hack). However, it did something to Word 2016, where all my .doc & .docx files were opened by Word 2003 & Word 2016 wasn't an option under "Open with...". I ended up restoring everything from Macrium Reflect.

I will now start with step 3.2.

 

Cumulative Update KB4514359 .NET Framework 3.5, 4.8 Windows 10 Sept.10 Win Update

Update: Cumulative Update KB4522738 .NET Framework 3.5, 4.8 Windows 10 Sept.26

Cumulative Update KB4522739 .NET Framework 3.5, 4.8 Windows 10 Sept.26