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

Some fixes feel satisfying in the moment, only to boomerang back as the same problem a week, a month, or a season later.

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 ...

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

If your Windows computer is stuck in an infinite reboot loop, it can be frustrating and challenging to resolve. However, there are several methods you can try to fix this issue and get your system up ...

Windows 11 KB5074109 is wreaking havoc thanks to several issues, with the most serious keeping users out of the operating ...

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

Frustrated with Windows 11 startup logo stuck issue? Discover proven troubleshooting fixes for 2026, from quick reboots to ...

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 ...