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ajeesh0910ayilyam's avatar
ajeesh0910ayilyam
Copper Contributor
Oct 21, 2026

Windows server 2022 is not updating with latest patch KB5126655

Windows server 2022 is not updating with latest patch KB5126655. However, successfully installed 2026-10 Cumulative update for .Net framework. Last successful Cumulative update for the operating system version 21H2 is 2026-06.

Try to update the latest patch manually, the server is rolling back the patch.

Active Directory
Compute
Hyper-V
windows server

4 Replies

  • Foxiiik's avatar
    Foxiiik
    Copper Contributor
    Nov 05, 2026

    I had the exact same issue. I managed to fix it after spending some time with it...

    Long story short:

    The update corrupts the Bootmgr.

    Recovery process:

    2x USB (1 with WinServ22) and another one is clean.

    Boot into windows Recovery using the USB.

    Roll the update back.

    Create a new bootmgr on your second usb.

    Reboot, remove USB with WinServ22.

    During reboot go the boot selector and select your 2nd usb with the Bootmgr, boot from that using Legacy boot not UEFI. That will "finish" the update and allows you to boot into windows.

    Once in windows, copy over the bootmgr from your usb to the boot partition (will need to remove/add permissions to be able to do it) once that is complete, you can boot up the server normally without the USB. 

  • szymonn841's avatar
    szymonn841
    Copper Contributor
    Oct 27, 2026

    There is a bigger issue on Supermicro motherboards when Intel SATA RAID is configured: the system fails to boot after an update. I have verified this on three different boards; X9SCL-F, X11SCW-F, X11SSL-F

    the issue occurs after a second restart : A disk read error occurred

    • fuzzysteve's avatar
      fuzzysteve
      Copper Contributor
      Oct 28, 2026

      I'm seeing something similar with this. It's a significant issue for us. Don't suppose you've heard anything from microsoft on it?

  • WinEndpointOps's avatar
    WinEndpointOps
    Brass Contributor
    Oct 22, 2026

    Four months without a successful cumulative update, and a clean rollback when you install manually, usually points to component store trouble or a failed prerequisite, not to this specific KB. The rollback leaves a trail, so I would start there:

     

    • Get the actual error code. In Event Viewer, look at Windows Logs > Setup and System around the install time, or run Get-WindowsUpdateLog. Codes like 0x800f0922, 0x800f0831 or 0x80073712 each point to a different fix, so the code matters more than the KB number.
    • Check the CBS log at C:\Windows\Logs\CBS\CBS.log and search for the last Error lines before the rollback. They name the package or file that failed.
    • Repair the component store: DISM /Online /Cleanup-Image /RestoreHealth, then sfc /scannow, then reboot and retry. If DISM cannot get its source files, point it at a Server 2022 ISO with /Source and /LimitAccess.
    • Free space and pending work. Make sure the system drive has several GB free, no pending reboot is stuck (check for a pending.xml in C:\Windows\WinSxS), and the servicing stack update from your June baseline is installed.
    • If it still rolls back, install the missing months in order (the latest Servicing Stack Update first, then the latest cumulative update) from the Microsoft Update Catalog, since an in-place repair needs a clean chain.

    If you post the error code and the last few CBS.log errors, people here can narrow it down much faster.