Windows 11 25H2: Update to 26H2 (KB5121794) shows "Completed", but build stays at 26200.9457

Martin Prohn 20 Reputation points
2026-10-28T18:16:04.9466667+00:00

On my PC running Windows 11 version 25H2 (build 26200.9457), Windows Update repeatedly shows the feature update "Windows 11, version 26H2" as "Completed". After a restart, the build is still 25H2 (26200.9457).

What I checked:

  • Get-HotFix -Id KB5121794 does not find the enablement package (not installed).
  • DisplayVersion = 25H2, UBR = 9457.
  • According to Microsoft's support page for KB5121794, KB5124010 (build 26100.9546) or a later cumulative update is a prerequisite. My build is below that, and the October updates also seem to be missing.
  • According to the support page, the Microsoft Update Catalog does not offer KB5121794.
  • The policy NoAutoUpdate = 1 (HKLM\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU) was set. I removed it, restarted the Windows Update service and searched again. Result unchanged: "Completed", build still 26200.9457.

Questions:

  1. Why is 26H2 shown as completed although the enablement package is not installed?
  2. What prevents the cumulative update to 26200.9546 or later from installing?
  3. How can I force the update or narrow down the cause?

A screenshot of the Windows Update page is attached.

Windows for home | Windows 11 | Windows update
0 comments
Answer accepted by question author
Ramesh 183.6K Reputation points Volunteer Moderator
2026-10-29T03:23:14.0533333+00:00

Please install the October 2026 Cumulative Update using DISM.

  • Create a folder named MSU in the C drive's root.
  • Download these two MSU files to C:\MSU. 
https://catalog.sf.dl.delivery.mp.microsoft.com/filestreamingservice/files/d8b7f92b-bd35-4b4c-96e5-46ce984b31e0/public/windows11.0-kb5043080-x64_953449672073f8fb99badb4cc6d5d7849b9c83e8.msu

https://catalog.sf.dl.delivery.mp.microsoft.com/filestreamingservice/files/4225b261-8248-43e5-a808-34f3faafe3f6/public/windows11.0-kb5127648-x64_2b88d2d308adc938fcd4d2876a68ee0b2a3c4c09.msu
  • From Command Prompt admin, run: 
DISM /Online /Add-Package /PackagePath:C:\MSU\windows11.0-kb5127648-x64_2b88d2d308adc938fcd4d2876a68ee0b2a3c4c09.msu

Restart Windows if prompted. If the update fails, share your CBS logs.

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