2025-10 Cumulative Update for Windows Server 2019 (KB5066586) Undoes Update on Reboot

So even though I ran DISM /Online /Cleanup-Image /ScanHealth, and no errors were found, you still recommend running DISM.exe /Online /Cleanup-Image /RestoreHealth ?  I am glad to give it a try.

I don't have a similar image to copy from unfortunately.

I checked the CBS log file, but it does not go back far enough to get information on the install failure.  I'll save this log file after my next attempt.  I am also going to update the drivers on this server.

I will rerun DISM with the RestoreHealth option this Saturday and report back.

This has been a tough one to diagnose. I greatly appreciate you help with this.