Windows 11 23H2: January Updates Break Sleep Mode and Shutdown

Microsoft has confirmed problems affecting systems running Windows 11 version 23H2 after installing the January 2026 security updates. According to the company, affected PCs may no longer shut down properly or enter sleep mode.

The issue has now been documented in the Windows Release Health notes. Microsoft states that after installing the January 13, 2026 security updates, systems with Secure Boot enabled can fail to power down or switch to sleep. Instead of shutting down or suspending, the devices may restart automatically. Secure Boot relies on virtualization-based security to protect the system against firmware-level attacks during startup.

Microsoft says the problematic update, identified as KB5073455, is only being offered for the Enterprise and IoT editions of Windows 11 23H2. While the knowledge base entry references changes related to Secure Boot, these changes are intended to update Secure Boot certificates rather than alter power management behavior.

Temporary workaround available

Until a permanent fix is released, Microsoft recommends a manual workaround for shutting down affected systems. Users should open a command prompt, for example by typing cmd into the Start menu search, and then run the command:

shutdown /s /t 0

This forces the system to shut down immediately. Microsoft has explicitly stated that there is currently no workaround for sleep mode. Users are advised to save their work and shut down their devices manually after use to avoid unintended restarts or battery drain.

This is the second issue Microsoft has acknowledged in connection with the January Patch Day updates. Earlier reports confirmed that the same updates can disrupt connections to Azure Virtual Desktop and Windows 365, affecting enterprise environments that rely on cloud-based Windows services.