Microsoft: Some Windows servers enter reboot loops after April patches

What happened

Microsoft has warned that a subset of Windows servers are entering reboot loops after installing April cumulative updates. It has been reported that domain controllers — the very machines that keep Windows-based networks humming — are among those affected, forcing repeated restarts and, in some cases, loss of authentication services. Painful for any IT team. Painful for users who suddenly can't log in.

The scope and reaction

Details remain somewhat fluid; Microsoft flagged the problem and is investigating. Administrators on forums and social channels allegedly saw servers rebooting shortly after boot, leaving teams scrambling for recovery plans and emergency rollbacks. Who hasn't been on a midnight patch round that went sideways? The emotional sting here is clear: win the security battle, lose the availability war.

Impact and immediate remedies

The fallout is primarily operational — authentication failures, interrupted services, and urgent change windows. Microsoft has provided guidance for affected customers, and it has been reported that rolling back the problematic update or restoring from recent system snapshots can stop the loop. If you run domain controllers, isolate any troubled host and avoid broad, immediate rollouts until you confirm stability in a test ring.

Takeaway

This is a reminder of two truths: Patch Tuesdays still bite, and critical systems deserve staged deployment. Test first, push slowly, and keep recovery plans sharp. If you're hit, follow Microsoft's support instructions and consider contacting support directly — and maybe get some sleep when you can.

Sources: bleepingcomputer