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 ...

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

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

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

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

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.

It's not just January's one.

greetings. JUST recieved a new dell about a week ago and it has worked great since I got it. it was accidentily unplugged while it was on and now when i re-boot it says: unmountable_boot_volume. I ...

Today’s Mac Gem is a simple one, but it’s sure to be useful to developers, frequent users of Boot Camp, and anyone else who regularly boots their Mac from different startup volumes. A few years back, ...