Windows Server 2012 Foundation stuck in a reboot loop while installing updates. The server starts with a message "Configuring Updates - Stage 1 of 4", shortly after it reboots and the same happens again.
The issue was resolved by trying to start the server in Safe Mode (press F8 when the server is starting for advanced boot menu). When entering the Safe Mode, Windows displayed a message that some updates failed to install and rebooted again. Then server started (in normal mode) and loaded Windows without any issues (after a short message about rolling back failed updates).
Interestingly, Windows Update History didn't display any failed updates. There were four successfully installed updates:
- 2019-12 Servicing Stack Update for Windows Server 2012 for x64-based Systems (KB4532920)
- 2019-12 Security and Quality Rollup for .NET Framework 3.5, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows Server 2012 for x64 (KB4533096)
- Windows Malicious Software Removal Tool x64 - December 2019 (KB890830)
- 2019-12 Security Monthly Quality Rollup for Windows Server 2012 for x64-based Systems (KB4530691)
DELL PowerEdge T110
Windows Server 2012 Foundation