Microsoft is investigating reports that some Windows 11 devices are failing to boot with "UNMOUNTABLE_BOOT_VOLUME" errors after installing the January 2026 Patch Tuesday security updates. The issue ...

Microsoft has confirmed that some users might find their PC unable to boot after installing the January 2026 security update released on January 13. This is on top of the plethora of other issues that ...

Microsoft has linked recent reports of Windows 11 boot failures after installing the January 2026 updates to previously failed attempts to install the December 2025 security update, which left systems ...