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Microsoft Windows 11 boot failures after January 2026 updates

Service Disruption
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1 unique sources, 3 articles

Summary

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Microsoft says it has fully resolved a Windows 11 boot failure that affected some commercial physical devices running 25H2 and 24H2, where failed updates could leave systems stuck on "UNMOUNTABLE_BOOT_VOLUME". The issue was tied to a failed December 2025 update state and later boot failures after KB5074109 or later updates; Microsoft says the fix was delivered in KB5077181 on February 10, 2026, with virtual machines and home users not reported impacted.

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Timeline

  1. 16.02.2026 00:08 1 articles · 5mo ago

    Microsoft resolves Windows 11 boot failures in KB5077181

    Mitigation Patch Update

    Microsoft says the Windows 11 boot failure affecting commercial physical devices running 25H2 and 24H2 is fully resolved in KB5077181 released on February 10, 2026, after the issue was linked to failed December 2025 updates and boot failures after KB5074109 or later updates.

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  2. 25.01.2026 15:20 3 articles · 5mo ago

    Microsoft Windows 11 boot failures after January 2026 updates

    Initial Disclosure

    After the January 13, 2026 Windows security update and later updates, some Windows 11 physical devices began showing UNMOUNTABLE_BOOT_VOLUME boot failures. Microsoft is investigating whether the behavior is tied to KB5074109 or another Windows update regression.

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