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

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

Round and round we go.

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

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

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

Microsoft is shifting focus to fixing Windows 11 performance and reliability after months of buggy updates, boot failures, ...

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.

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

First, we are going to change the boot order as without doing so, the computer will boot from an empty hard drive or another source. So this step ensures that the computer boots from the installation ...

When Windows won’t boot up, it can be a disturbing experience. But that moment passes quickly, and you must decide how to get past this (hopefully) temporary hiccup. Fortunately, there are plenty of ...