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

Windows 11 KB5074109 (January 2026 Update) is causing major issues on some PCs, and Microsoft has more details to share.

A Windows security update bug has prevented some Windows 11 24H2 and 25H2 users from booting into their PCs, requiring them ...

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

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

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 ...

Error Code 0xc00000f0 generally occurs while upgrading Windows Installation, especially from Windows 10 to Windows 11. Users confirm that while upgrading the Windows ...

Microsoft has been rolling out Windows 11 24H2 for some time now, which has caused numerous problems — some so serious, in fact, that Microsoft has started blocking the update for affected systems. A ...

If Windows 11 installation starts all over again after reboot, execute the solutions mentioned below to resolve it. The installation may restart continuously instead of progressing to the next setup ...

Microsoft is investigating reports of serious boot failures affecting Windows 11 devices following the January 2026 security ...