Windows Server 2019 fails to boot after cumulative update
Recent cumulative updates cause Windows Server 2019 domain controllers to crash with a critical service failure and enter a boot loop during startup. Recovering the environment requires using the DISM command-line tool to revert pending actions. Subsequent patches can also break explorer.exe upon login.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
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Windows Server 2019 fails to boot after cumulative update
- 1Running dism /image:C:\ /cleanup-image /revertpendingactions to roll back the update and allow the server to start normally.Did this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“We've encountered a consistent issue across our environment where all Windows Server 2019 Domain Controllers fail to boot after installing the August and September 2026 cumulative updates.”source ↗
“After rebooting to complete installation, the server applies the update to 30%, then restarts, and when booting crashes during start-up with: CRITICAL_SERVICE_FAILED”source ↗
“The only successful recovery method we've found is: dism /image:C:\ /cleanup-image /revertpendingactions”source ↗
“Yup had problems with new updates since like 6 months. Last one is maybe same as yours. Explorer being killed after login when using sysprep”source ↗
“Their OOB patch KB5129241 seems to reinstall KB5124008, which seems to kill explorer.exe upon login, amongst many other things.”source ↗
Where this came up
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