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

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

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

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 ...

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

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 ...

Some users have complained about this problem that when they start their computer, it doesn’t boot. Instead, a Default Boot Device Missing or Boot Failed blue ...

Use Automatic Startup Repair Verify the boot order Verify the hardware connection Use System Restore Repair the computer using Installation Media To learn more about ...