After installing KB5078822 successfully Update on windows server 2022 for March 2026 unable to install secuity update KB507876 for March 2026

Hi Mohan Ambikar,

Thanks for giving that a shot and for bringing back those detailed troubleshooting results! It likely contains a Servicing Stack Update (SSU), which makes it a permanent component that Windows will refuse to uninstall.

That IsPostback_RC_PendingUpdates error you found is the "smoking gun" we were looking for. What this tells us is that the Windows Update engine is trapped in a "zombie" pending state. It thinks it is permanently in the middle of a reboot or an update operation that it can never quite finish. Because it thinks it's busy, it's locking the system down, which perfectly explains why it refuses to install the new KB.

Since clearing the cache didn't break the lock, we need to forcefully tell the OS to abandon whatever update action it thinks is pending.

Here is the next level of escalation to clear that stuck state:

1. Force-Revert Pending Actions Open an elevated Command Prompt as Administrator and run this exact command to force the Component-Based Servicing (CBS) engine to cancel all pending update tasks: dism.exe /online /Cleanup-Image /RevertPendingActions

2. Reboot Immediately Do not skip this step. Restart the server immediately so the system can process that cancellation command during the boot cycle.

3. Clear the Pending.xml File After the server comes back up, open Command Prompt as Administrator again and run these commands to ensure no lingering pending files are tricking the system into locking up again:

takeown /f C:\Windows\WinSxS\pending.xml
icacls C:\Windows\WinSxS\pending.xml /grant administrators:F
ren C:\Windows\WinSxS\pending.xml pending.old

(Note: If the system says the file cannot be found, that is completely fine—it just means the DISM command in step 1 successfully wiped it).

4. Try the Manual Install Again Once that pending state is completely flushed out, try running the standalone .msu installer for KB5078766 again.

I want to be completely candid with you: if this RevertPendingActions trick doesn't clear the jam, it means the registry's core servicing keys are deeply corrupted. In that specific scenario, the AI bot's earlier suggestion of doing an in-place repair upgrade using the Windows Server 2022 ISO might actually be your most time-effective way out to save the server without losing your data and installed roles.

Fingers crossed we don't have to go that far. Give this revert process a try and let me know the results!

Tracy.

Hi Mohan Ambikar,

This is actually a classic sequence collision in the Windows Update engine. The error code 2148081668 (CRYPT_E_NOT_FOUND) usually means the Component-Based Servicing (CBS) engine is failing a cryptographic signature check or cannot find a required manifest property to process the new update. The second error you saw when trying to uninstall, 2149851140, typically means the CBS store is stuck in a pending operation state.

Since your other servers skipped KB5078822 and installed KB5078766 perfectly fine, the first update simply left your CBS store and cryptographic catalog in a tangled, locked state.

Let's untangle it without rebuilding your OS. Please try this proven sequence from an elevated Command Prompt to forcefully clear the locks:

1. Reset the Update Cache and Cryptographic Catalogs Run these commands one by one to stop the update services, rename the broken catalogs (forcing Windows to build fresh ones), and restart them:

net stop wuauserv
net stop cryptSvc
net stop bits
net stop msiserver
ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
ren C:\Windows\System32\catroot2 catroot2.old
net start wuauserv
net start cryptSvc
net start bits
net start msiserver

2. Repair the Component Store Now, force Windows to check for and repair any broken update manifests that KB5078822 might have left behind:

DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow

3. Manual Installation Restart your server once. After the reboot, instead of relying on the Windows Update menu, download the standalone .msu installer for KB5078766 directly from the Microsoft Update Catalog and run it manually.

In the vast majority of these cases, clearing out that catroot2 folder resolves the CRYPT_E_NOT_FOUND error. Give this a try and let me know if it helps you get that March security update successfully installed!

Tracy.

Error 2148081668 (“cannot find object or property”) and 2149851140 when installing or uninstalling Windows updates typically indicate a problem in the servicing stack or update state on that specific server, not a general issue with the KB itself. The context provided does not include specific guidance for KB5078822 or KB5078766, but it does include general guidance about security updates and their risks.

Given that KB5078766 installs successfully on another Windows Server 2022 machine where KB5078822 is not present, the problematic server is likely in a corrupted or inconsistent update state. In such cases, the recommended approach is:

1. Avoid uninstalling security updates unless absolutely necessary, because uninstalling can expose the server to vulnerabilities and may cause instability.
2. Treat the server as potentially corrupted and plan remediation that preserves security posture, such as:
   • Ensuring the server remains protected (e.g., network segmentation, limited exposure) while troubleshooting.
   • Considering an in-place repair/upgrade of Windows Server 2022 using current installation media with the latest Dynamic Update applied (KB5079518 describes Dynamic Update components for Windows Server 2022 setup). This approach refreshes setup and servicing components while keeping roles and data.
   • If repair is not feasible or fails, planning a rebuild/migration to a cleanly installed Windows Server 2022 instance that is fully patched.

Uninstalling KB5078822 is not recommended as a primary mitigation path, both because of the errors encountered and because removing security updates increases vulnerability to attacks, can compromise data, and may affect supportability.

If CBS.log or setup logs are needed for deeper analysis, they should be reviewed by Microsoft Support. For complex update failures like this, opening a support case and providing the logs is the appropriate next step.

References:

• KB5079518: Setup Dynamic Update for Windows Server 2022: March 10, 2026
• Understanding the risks: Why you should not uninstall security updates