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.

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

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

According to reports from Microsoft and Windows Latest, the latest update, identified as KB5074109, has caused some Windows devices to fail to boot entirely. Users encountering this problem will see a ...

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

Windows 11 Enterprise and IoT get an update disrupting shutdown and hibernation functionality, but a more manual shutdown is ...

Windows 11 KB5074109 is causing crashes, reboots, black screens, and BSOD errors for some users, but workaround is available.

Microsoft’s latest Windows 11 security update was meant to harden PCs against stealthy firmware attacks. Instead, it has ...

Microsoft’s first Windows 11 security update of 2026 broke shutdowns and some Remote Desktop sign-ins. Microsoft has released ...

Microsoft has issued a warning to Windows 11 users over a recent optional software update that has been causing multiple problems. The company says patch KB5043145 is causing some computers to restart ...

Microsoft warns that some Windows 11 systems enter reboot loops or might freeze with blue screens after installing the September 2024 KB5043145 preview update. This month's KB5043145 optional update ...

Beware the BitLocker startup loop after Windows 10 update. Update, May 18, 2025: This story, originally published May 17, has now been updated with a statement from Microsoft regarding the Windows 10 ...