I am struggling to remember the last time my server stopped working after a Microsoft update. In spite of that, I still use the Windows Blue Screen (BSOD) graphic as a way to emphasize how important it is for Windows users to have backups, and Windows admins to have backups and a virtual lab to test Microsoft patches and updates before unleashing them onto any Windows machines in the infrastructure.
This weekend I was notified by Microsoft Windows Update that my Domain Controller (DC) needed a Windows update. Of course, the first action was to press the update button; it’s a simple task, and what could go wrong?
I might have been a bit hasty there…after a short while, I started receiving notifications that some servers in my lab had stopped responding, starting with my Exchange Server. Next to call me was my CRM environment, then my Virtual Center; finally, even my home automation server stop responding.
I checked my DNS Server; this server is also my Domain Controller (DC). Yes, this is where I so casually pressed the Update button to update my Windows 2016 server.
My first response was to boot into Windows Safe Mode. After some troubleshooting steps, I was able to manually remove the latest update. I then restarted the installation of the same upgrade; but this time, I was watching.
The second run of the upgrade task completed successfully, and the server attempted a reboot. I was surprised to be greeted with the following error: “Windows update failed upon restart and is trying to roll back – do not shut down your computer”.
To fix this error, I forced the server to boot back to Safe Mode. I then removed the latest update manually, and then rebooted the server to make sure things were back to normal; but my DC kept booting to Safe Mode.
To remedy this problem, I used the following command:
bcdedit /deletevalue safeboot
I then rebooted.
If you ever experience this issue after a Windows update, or need a DC restoration from a backup, those steps we have just described will definitely help you back to a normal boot. For me, I now have a good story to tell my customers, and use this experience to impress upon them the importance of regular backups; I can tell first hand that sometimes the Windows Upgrade process can go wrong.