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

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

After the first update stopped PCs from shutting down or going to sleep, the latest one halts the boot-up process. Microsoft says it's investigating the problem.

Some machines are failing to start after security updates, prompting yet another Microsoft investigation Microsoft is investigating reports that its January 2026 security updates are leaving some ...

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

Neowin also notes another dark side to this latest issue. “Interestingly, Microsoft came up with a technical solution for ...

The most recent January Windows Update is broken on a number of PCs, but at least virtual machines don't seem to be impacted.

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

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.

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

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