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

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

Everyone knows you need to keep your operating system up to date, but what happens when a company botches the update and ...

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

Another week, another big Windows problem.

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

Some machines are failing to start after security updates, prompting yet another Microsoft investigation Microsoft is ...

Microsoft shares more details about the boot failure bug triggered by the latest Patch Tuesday update, KB5074109, in Windows ...

A fresh wave of Windows 11 update trouble is making the rounds, and this one is about as disruptive as it gets: some PCs reportedly can’t boot after installing the latest January 2026 security update.

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

Microsoft has started automatically replacing expiring Secure Boot certificates on eligible Windows 11 24H2 and 25H2 systems. Secure Boot is a security feature that blocks malicious software (like ...