Error 0x80040905 in Windows Server 2025 Datacenter after installing KB5065426.

Question

Error 0x80040905 in Windows Server 2025 Datacenter after installing KB5065426.

Terry Rivera 0

After KB5065426 was installed and server rebooted, I would select Windows Updates in Server Manger console it would return error "Unknown error (0x80040905) An error occurred starting task ms-settings:windowsupdate."

I uninstalled KB5065426 and functionality returned to normal.

Terry Rivera 0 Reputation points

2025-09-16T17:05:06.7933333+00:00

Thank you for your input, I had run sfc /scannow DISM.exe /online /cleanup-image /restorehealth on a few of the servers patched. These servers are built on VMWare and everyone that receive the KB has this issue. Here are all KB's that were downloaded and installed at the same time

KB5065426 SEPT Cumulative patch OS Build 26100.6584

KB5064401 .NET Framework 3.5 and 4.8.1

KB5063878 addressed a security vulnerability (CVE-2025-50173) by requiring administrator credentials for MSI repair operations. This prevented unauthorized changes to the system by standard users during these operations.

2 answers

Your answer

Terry Rivera 0 Reputation points

2025-09-16T17:05:06.7933333+00:00

Thank you for your input, I had run sfc /scannow DISM.exe /online /cleanup-image /restorehealth on a few of the servers patched. These servers are built on VMWare and everyone that receive the KB has this issue. Here are all KB's that were downloaded and installed at the same time

KB5065426 SEPT Cumulative patch OS Build 26100.6584

KB5064401 .NET Framework 3.5 and 4.8.1

KB5063878 addressed a security vulnerability (CVE-2025-50173) by requiring administrator credentials for MSI repair operations. This prevented unauthorized changes to the system by standard users during these operations.

Answer 1

Hello Terry,

The error 0x80040905 typically indicates a failure to launch the ms-settings:windowsupdate task, which is tied to the modern settings interface. This can happen if the update modifies system components or registry entries that affect task execution or UI integration.

Since uninstalling KB5065426 restored functionality, it’s likely that the update introduced a regression or compatibility issue. Microsoft has acknowledged similar problems with this cumulative update, especially when paired with certain servicing stack configurations.

Here are a few suggestions moving forward:

Hold off on reinstalling KB5065426 until Microsoft releases a revised version or documents a workaround.

Monitor the official KB page and Microsoft Q&A thread for updates or hotfix announcements.

If the update is critical for security compliance, consider applying it in a test environment first and using PowerShell or WSUS for update management to bypass the Server Manager UI.

You may also want to report the issue via the Feedback Hub or your enterprise support channel to help escalate visibility.

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If this answer helps, feel free to hit “Accept Answer” so others can benefit too 😊.

T&B, Harry.

Answer 2

Adam J. Marshall 10,456 MVP

This looks like it's local. I have it installed and it's working fine.

User's image

You should try

sfc /scannow
DISM.exe /online /cleanup-image /restorehealth

More info here: https://www.ajtek.ca/wsus/another-successful-in-place-upgrade-why-not-change-how-you-think/

Terry Rivera 0 Reputation points

2025-09-16T17:04:10.1066667+00:00

Thank you for your input, I had run sfc /scannow DISM.exe /online /cleanup-image /restorehealth on a few of the servers patched. These servers are built on VMWare and everyone that receive the KB has this issue. Here are all KB's that were downloaded and installed at the same time

KB5065426 SEPT Cumulative patch OS Build 26100.6584

KB5064401 .NET Framework 3.5 and 4.8.1

KB5063878 addressed a security vulnerability (CVE-2025-50173) by requiring administrator credentials for MSI repair operations. This prevented unauthorized changes to the system by standard users during these operations.
Adam J. Marshall 10,456 Reputation points MVP

2025-09-17T12:20:18.29+00:00

KB5063878 is August's CU, so it would be replaced by KB5065426.

Try installing KB5065426 again.

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Error 0x80040905 in Windows Server 2025 Datacenter after installing KB5065426.

2 answers

Your answer