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

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

Microsoft’s first major Windows 11 update of 2026 released on January 13 introduced a concerning bug that caused some PCs to ...

Windows 11 Enterprise and IoT get an update disrupting shutdown and hibernation functionality, but a more manual shutdown is ...

Microsoft’s first Windows 11 security update of 2026 broke shutdowns and some Remote Desktop sign-ins. Microsoft has released ...

Windows 11 KB5074109 is causing crashes, reboots, black screens, and BSOD errors for some users, but workaround is available.

Microsoft has acknowledged a serious power-state regression affecting Windows 11 version 23H2 systems after the January 2026 ...

After the first update stopped PCs from shutting down or going to sleep, the latest one halts the boot-up process. Microsoft ...

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

The first Windows 11 update for 2026 has caused unexpected trouble to some users and prevented the affected computers from ...

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

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