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

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.

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

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

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

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

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 ...

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.