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 ...

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

Microsoft has linked recent reports of Windows 11 boot failures after installing the January 2026 updates to previously ...

Neowin also notes another dark side to this latest issue. “Interestingly, Microsoft came up with a technical solution for ...

greetings. JUST recieved a new dell about a week ago and it has worked great since I got it. it was accidentily unplugged while it was on and now when i re-boot it says: unmountable_boot_volume. I ...

Ok. Here goes. I was running 2000 Pro without a hitch, with 2 hdd's. A 30gb Maxtor, and a 60gb IBM 60gxp. I installed XP pro, and on restart I got the unmountable_boot_volume blue screen. Reset the ...