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What Critical Mistake in Windows 11 Update KB5058405 Caused Widespread Boot Failures?
The cumulative update KB5058405 for Windows 11 versions 22H2 and 23H2, released on May 13, 2025, introduced quality improvements and security patches. However, it also caused a serious issue on certain systems, leading to a Blue Screen of Death (BSOD) with error code 0xc0000098. The root cause was a problem with the ACPI.sys driver, which is essential for power management and hardware configuration in Windows.
Error Description
After installing KB5058405, affected devices fail to boot and display a recovery error:
“Your PC/Device needs to be repaired. The operating system couldn't be loaded because a required file is missing or contains errors. File: ACPI.sys. Error code: 0xc0000098”.
Primary Impact
The issue primarily affects virtual machines, including:
- Azure Virtual Machines
- Azure Virtual Desktop
- On-premises VMs hosted on Citrix or Hyper-V
Home users running Windows 11 Home or Pro are generally not impacted, as these environments rarely use virtual machines.
Scope
Microsoft reported the bug affects a small number of physical devices, but it is more prevalent in enterprise and IT environments with virtual infrastructure.
Technical Explanation
ACPI.sys:
The Advanced Configuration and Power Interface (ACPI) driver is a core Windows component responsible for managing hardware resources and power states. Corruption or malfunction in this driver can prevent Windows from loading, resulting in a BSOD.
Resolution: Out-of-Band Update KB5062170
To address the issue, Microsoft released an out-of-band cumulative update, KB5062170, on May 31, 2025.
Important Points About KB5062170
Purpose:
- Specifically fixes the ACPI.sys 0xc0000098 recovery error caused by KB5058405.
- Includes all prior fixes and improvements from the May 2025 updates but does not introduce new security patches beyond those already released.
Availability:
- Only available for manual download via the Microsoft Update Catalog.
- Not distributed through Windows Update.
- Should only be installed on systems experiencing the ACPI.sys error; systems that installed KB5058405 without issue do not need this update.
Installation:
- Cumulative—no need to install previous updates beforehand.
- Requires a system restart after installation.
Known Issue:
Users may encounter display issues with Noto fonts in Chromium-based browsers when system scaling is set to 100%. Increasing scaling to 125% or 150% is recommended as a temporary workaround.
Recovery Steps for Affected Systems
If the device is stuck in recovery mode: Restart Windows on recovery-enabled devices.
For non-recovery-enabled virtual machines:
- Mount the virtual hard disk (VHD) from a remote device.
- Attach the VHD to another VM as a data disk, then return it to the original VM.
- Restart Windows in normal mode to revert to the last successful update.
For Azure users: Follow Microsoft’s repair steps for Windows VMs, as outlined in their official documentation.
After recovery: Download and install KB5062170 from the Microsoft Update Catalog to permanently resolve the issue.
Key Takeaways
- The KB5058405 update for Windows 11 22H2/23H2 can cause critical boot failures in virtualized environments due to ACPI.sys corruption.
- Microsoft’s KB5062170 out-of-band update provides a targeted fix and should be manually installed if your system is impacted.
- Home users are largely unaffected, but IT administrators should act promptly to protect enterprise infrastructure.
Actionable Recommendation
If you manage Windows 11 virtual machines and have not yet applied the May 2025 update, install KB5062170 instead of KB5058405 to prevent downtime. For affected systems, follow the recovery and update steps above to restore normal operations.