Windows 11 May 2025 Update Causes Boot Failures: How to Fix with Emergency Patch KB5062170

Here's a concise summary of the Microsoft emergency update situation, drawn from both your initial news source (HotHardware) and the latest discussions and advisories from experts and IT forums:

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Issue Summary​

• Problem Update: Windows 11 May 2025 security update (KB5058405)
• Impacts: Mainly Windows 11 versions 22H2 and 23H2 in virtualized environments (Azure, Citrix, Hyper-V).
• Symptom: Affected machines enter recovery mode and become unbootable, showing errors like “Your PC/Device needs to be repaired. The operating system couldn’t be loaded because a required file is missing or contains errors,” frequently related to ACPI.sys and 0xc0000098 errors .

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Microsoft's Response​

• Emergency Patch: Out-of-band update KB5062170, specifically designed to prevent or fix these boot failures triggered by KB5058405.
• Release Date: Emergency patch released promptly in response to widespread reports.

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Mitigation and Recommendations​

• If NOT Updated Yet:
• Critical: Install the KB5062170 out-of-band update before attempting to deploy the May 2025 security update (KB5058405) on any Windows 11 22H2 or 23H2 system, especially in virtual desktop/VM environments.
• If Already Affected (Cannot Boot):
• For Azure VMs: Use Azure VM repair commands and recovery tooling.
• For on-prem or non-Azure, you may need to use WinRE/boot media to try and reverse the problematic update or apply the new patch offline.

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Additional Notes​

• This is one of several recent Windows update blunders, including Windows 10 May 2025 BitLocker recovery loops and accidental, unintended upgrades.
• Out-of-band (OOB) updates like KB5062170 are released outside Patch Tuesday to deal with urgent, high-impact problems. Always check for these in major IT environments before blanket-deploying cumulative security updates.

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Key Actions for Admins​

• Pause KB5058405 deployments across at-risk fleets.
• First install KB5062170 on all Windows 11 22H2/23H2 machines, especially VMs.
• Monitor the Microsoft Health Dashboard and trusted IT forums for further details and troubleshooting.

For detailed technical steps or official Microsoft release notes, refer to the Microsoft Update Catalog or IT support documentation.

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Let me know if you'd like step-by-step remediation or deployment instructions!

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Source: HotHardware Microsoft Released An Emergency Windows Patch Over The Weekend, Get It Now