Windows update failed (KB4506991 & KB4512508)

Reka · 23 Aug 2019

My computer tries to install and update these files:
KB4506991 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10, version 1903
KB4512508 (OS-build 18362.295)

Ï have tried pretty much everything of troubleshooiting I have read online. I have tried to download and install the files manually from https://www.catalog.update.microsoft.com/home.aspx.

But yet I get update failed, all the time. When my computer tries to install the new updates, when it restarts it somehow stops at 7%, and then I get told that the update failed. It seems that it wont go past 7%, hence why the download might be failing.

Any help on this please? I am really frustrated since this is a brand new computer..

dalchina · 24 Aug 2019

Hi, you might try downloading it (them) manually from the links posted in the article per update per build in the News section:
Cumulative Update KB4512508 Windows 10 v1903 build 18362.295 - Aug. 13
https://www.tenforums.com/windows-10-news/136266-cumulative-update-kb4506991-net-framework-3-5-4-8-windows-10-july-9-a.html

Otherwise you could have a look at your Windows Update log. (Google if unsure)

Also consider the Windows Update troubleshooter and
Reset Windows Update in Windows 10

Reka · 24 Aug 2019

Hi dalchina, thank you for your reply.

I have tried to download the following updates manually, but when the computer restart is required, it fails to update yet again. I also tried to reset Windows Update as you suggested, and after I followed all the instructions I tried to update Windows again, and it failed. Honestly I am totally lost on what to do. Is a total factory reset required to fix this issue? This really sucks! Any other advice is very appreciated.

Pejole2165 · 24 Aug 2019

Hi, this is exactly what happened to me, the update always got to 7% updating, then re-booted and displayed "unable to update...undoing changes. This happened several times, I tried downloading myself and running the update...failed the same, tried SFC and DISM (including the batch file from these forums)….still kept failing at 7%...even though SFC and DISM reported no issues. The only way I fixed this was to use MMCT to download the ISO and do an in place upgrade. This worked for me.
I would suggest if you want to try this method make a complete system image with Macrium Reflect on an external drive and even make a second backup of any critical (to you) files.
There are excellent tutorials on this forum for Macrium Reflect and for using other backup methods.
An in place upgrade should only be performed if all else fails and only if you are comfortable with using this method.

dalchina · 24 Aug 2019

Thanks for sharing that.

In-place upgrade repair install:
Download compatible 1903 iso using Microsoft Media Creation tool (Google)
Rt click the iso file
Click Mount (Mount will not be available if you have associated iso with another program)
Open the newly created drive letter in file explorer
Double click Setup.exe

You can choose to accept updates during this, or not.

(Tutorial available for this).

Pejole2165 · 24 Aug 2019

I'll just add to that, the MMCT offers an upgrade this PC option when it runs, this is the option I chose and it kept all my files and apps.