Windows Report

KB5074109 Update Causes Boot Failures on Windows 11 Devices

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

Microsoft investigates Windows 11 boot failures after January updates

Microsoft is investigating reports that some Windows 11 devices are failing to boot with "UNMOUNTABLE_BOOT_VOLUME" errors ...
Tom's Hardware on MSN

Some PCs can't boot after latest Windows 11 security update, no fix in sight — mostly affects 24H2 and 25H2 versions

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

The first big Windows update of 2026 is a glitchy mess - here's the full list of bugs and fixes

The first big Windows update of 2026 is a glitchy mess - here's the full list of bugs and fixes ...