KB5066791 update won't install on fresh Windows 10 22H2 installation

Question

I had to reinstall my laptop with WIndows 10 22H2.
When I then install updates the KB5066791 update fails.

It starts to install. Reboots at 21% (not the usual 30%)
and after reboot it goes to 98% (uses almost forever from 92%)
then roll back two times (takes almost forever times two :-)

Since this is a fresh install I can't see what is wrong.

When I rerun "windows update" there is no wrror code either.
The update is just offered again when I do a new search :-/

Answer 1

Hi, I'm Bernard, a fellow Windows user. I'm happy to help!

Just to confirm, have you already enrolled in the Extended Security Updates (ESU) program? If not, this may be the reason why you’re unable to update your Windows 10, as standard Windows updates ended last October. T

o enroll in ESU, please follow the steps in the link below:

https://www.microsoft.com/en-us/windows/extended-security-updates

If you have already enrolled and have the same issue, I suggest doing an in-place upgrade, wherein it will update the device to the latest version and repair all issues without deleting any files.

 

Note: before doing this, make sure to create a restore point:  https://support.microsoft.com/en-us/help/4027538/windows-create-a-system-restore-point

 

1. Go to this link: https://www.microsoft.com/en-us/software-download/windows10
2. Select Download Now, and select Run. You need to be an administrator to run this tool.
3. On the License terms page, if you accept the license terms, select Accept.
4. On the What do you want to do? page, select Upgrade this PC now, and then select Next.
5. After downloading and installing, it should fix the issue.

 

Reference: https://www.microsoft.com/en-us/software-download/windows10

Answer 2

KB5066791 has known installation issues on some Windows 10 22H2 systems, even when the installation is fresh and DISM/SFC are clean. In at least one confirmed case, the update repeatedly failed and rolled back, but was successfully installed by letting it complete while booted via Safe Mode.

Use the following workaround that has been verified to fix KB5066791 failures:

1. Let Windows Update download and stage KB5066791 so that Windows is prompting for a restart (or shows it as pending install).
2. Instead of choosing “Restart and update”, perform a normal restart into the Windows Recovery Environment:
   • Open the Start menu, select Power, then hold Shift and click Restart.
3. In the recovery menu, choose the option to boot into Safe Mode.
4. Allow the system to boot into Safe Mode. Do not run additional tools; simply choose to restart the PC again from Safe Mode.
5. On this restart, Windows will automatically attempt to complete the KB5066791 installation before loading the desktop.
6. Let the process finish (it may reboot more than once). After returning to the desktop, open Settings > Update & Security > Windows Update and verify that KB5066791 is listed as successfully installed and is no longer being offered.

This behavior suggests that a normal-boot service or driver interferes with the update when installed in the standard environment, while Safe Mode allows setup to complete.

If the update still fails after this Safe Mode sequence, use the in-place reinstall/repair option that keeps files and apps, which has resolved stubborn update failures in other cases: see Fix issues by reinstalling the current version of Windows and run it from Settings > Update & Security > Recovery > Fix problems using Windows Update.

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References:

• KB5066791 fails with 0x80071A2D on Windows 10 22H2 (19045.6396) - Microsoft Q&A
• Resolved issues in Windows 10, version 22H2
• Windows Update: FAQ
• KB5079473 fail with 0x80073712 while inplace upgrade fail with 0x8007042B - Microsoft Q&A