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

Microsoft has had to issue two out-of-band updates to fix its buggy Windows 11 patch.

Windows 11 runs into another disastrous bug with its latest update — Microsoft admits an 'issue in which devices are failing ...

In a surprising turn of events, Microsoft has confirmed that its January 2026 security update, KB5074109, is causing significant boot issues for some Windows 11 users. This latest development ...

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

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

The first big Windows update of 2026 has bugs: Outlook freezes, app errors, and how to fix them ...

In confirmed cases, Windows 11 boot failure occurs post-update, with the machine stuck at a black screen and unable to ...

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

Windows 11 had a rough 2025. We tracked the top 20 Windows 11 issues reported by Windows Latest, from failed updates to ...

Microsoft’s January 2026 security update for Windows 11 is continuing to cause problems for users. This comes after the patch ...

The fix is for a bug that prevents some systems from shutting down, while another bug that prevents hibernation has no ...