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 ...

Some machines are failing to start after security updates, prompting yet another Microsoft investigation Microsoft is ...

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

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

Microsoft's latest security update for Windows 11 has caused unexpected problems for users who run both Windows and Linux on the same computer. After installing the update, many users have reported ...

Frustrated with Windows 11 startup logo stuck issue? Discover proven troubleshooting fixes for 2026, from quick reboots to ...

In confirmed cases, Windows 11 boot failure occurs post-update, with the machine stuck at a black screen and unable to ...

Experiencing a Windows 11 boot loop can be incredibly frustrating, transforming your computer into a seemingly endless cycle of restarts that disrupts productivity. When your system continuously fails ...

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.

Some fixes feel satisfying in the moment, only to boomerang back as the same problem a week, a month, or a season later.

Use these fixes if your Windows PC is stuck in a boot loop after a BIOS update. Before proceeding, disconnect all peripherals and check if your PC boots into Windows. Press and hold the power button ...