Windows 11 January 2026 updates may cause boot failures on some PCs. Microsoft is investigating issues linked to KB5074109.

Windows 11 shutdown bug explained with causes, fixes, and workarounds to stop restarts, battery drain, and failed power-offs after updates.

The first Windows 11 update for 2026 has caused unexpected trouble to some users and prevented the affected computers from shutting down or restarting properly.

This comes just hours after reports that another emergency update has been issued by Microsoft to affect other problems ...

Some machines are failing to start after security updates, prompting yet another Microsoft investigation Microsoft is ...

Microsoft is investigating reports that some Windows 11 devices are failing to boot with "UNMOUNTABLE_BOOT_VOLUME" errors ...

Microsoft has confirmed that a known issue preventing some Windows 11 devices from shutting down also affects Windows 10 systems with Virtual Secure Mode (VSM) enabled.