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

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 ...

Windows 11 KB5074109 is wreaking havoc thanks to several issues, with the most serious keeping users out of the operating ...

Microsoft is aware of an alleged issue that leaves PCs unable to boot and requires manual recovery after Windows 11 January ...