Windows 11 KB5077181 fixes boot failures linked to failed updates

Microsoft says it has resolved a Windows 11 bug that caused some commercial systems to fail to boot with an "UNMOUNTABLE_BOOT_VOLUME" error after installing recent security updates, with the fix ...

Windows 11 appears to have a boot failure bug that's caused by an update failure bug, creating a circle of, err, bugs

Round and round we go.
XDA Developers on MSN

Microsoft confirms that a stack of bad Windows updates is causing boot issues

It's not just January's one.
Bleeping Computer

Microsoft investigates Windows 11 boot failures after January updates

Microsoft is investigating reports that some Windows 11 devices are failing to boot with "UNMOUNTABLE_BOOT_VOLUME" errors after installing the January 2026 Patch Tuesday security updates. The issue ...