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.

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

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

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 ...

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

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 has confirmed that the boot failures with its January 2026 Windows 11 update are limited to “commercial” PCs and happened due to the December 2025 update failing to install and PCs being ...