Windows 11 KB5074109 (January 2026 Update) is causing major issues on some PCs, and Microsoft has more details to share.

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 ...

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

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

Hi all,<BR>I never really bothered to dual boot windows before, but since I got Win 7 Ultimate from attended the Philly dev conference 3 weeks ago, I figured it was about time to get it up and running ...

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 ...

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

For some reason lately my computer has been having very much trouble when booting up after sitting off for a couple hours. Once the computer is up and running, everything is perfectly fine, but ...

Here are the best free boot repair software and tools that you can use to fix boot issues on your Windows 11/10 PC: The first tool that we would like to list here is the Windows built-in Startup ...

While this ability to install use multiple operating systems on Macs is convenient, in some instances problems with a non-Mac OS X system installation can prevent users from being able to boot back ...

The easiest way to fix most of the problems in Windows 11/10 PC is to RESTART THE PC! It is also the first question asked by any person from who you seek technical help. Have you tried restarting the ...