May 13, 2025—KB5058405 (OS Builds 22621.5335 and 22631.5335)

This security update includes quality improvements. Key changes include:

• This build includes all the improvements in Windows 11, version 22H2.

• No additional issues are documented for this release.

This security update includes improvements that were part of update KB5055629 (released April 22, 2025). The following summary outlines key issues addressed by the KB after you install it. Also, included are available new features. The bold text within the brackets indicates the item or area of the change.

• [Secure Boot Advanced Targeting (SBAT) and Linux Extensible Firmware Interface (EFI)] This update applies improvements to SBAT for the detection of Linux systems.

• [Windows Update] Fixed: This update addresses an issue where you might be unable to update to Windows 11, version 24H2 via WSUS. The download might not start or complete, showing error code 0x80240069 and logs with "Service has unexpectedly stopped".

If you installed earlier updates, your device downloads and installs only the new updates contained in this package.

For more information about security vulnerabilities, see the Security Update Guide and the May 2025 Security Update.

Applies to: All users

Symptom

There are reports of blurry or unclear CJK (Chinese, Japanese, Korean) text when displayed at 96 DPI (100% scaling) in Chromium-based browsers such as Microsoft Edge and Google Chrome. The March 2025 Preview Update introduced Noto fonts in collaboration with Google, for CJK languages as fallbacks to improve text rendering when websites or apps don’t specify appropriate fonts. The issue is due to limited pixel density at 96 DPI, which can reduce the clarity and alignment of CJK characters. Increasing the display scaling improves clarity by enhancing text rendering.

Workaround

As a temporary workaround, increase your display scaling to 125% or 150% to improve text clarity. For more information, see Change your screen resolution and layout in Windows.

We are investigating this issue and will provide more information when it is available.

Applies to: All users

Symptom

While installing the May 2025 Windows security update, some devices might encounter the following 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

This issue has been observed on a small number of physical devices, but primarily on devices running in virtual environments, including:

• Azure Virtual Machines

• Azure Virtual Desktop

• On-premises virtual machines hosted on Citrix or Hyper-V

Home users of Windows using Home or Pro editions are unlikely to face this issue as virtual machines are mostly used in IT environments.

The ACPI.sys file (Advanced Configuration and Power Interface) is a critical system driver responsible for managing hardware resources and power states.

Workaround

This issue is addressed in KB5062170.

If you have not yet deployed the May 2025 Windows security update (KB5058405) and your IT environment includes devices running in a virtual desktop infrastructure—such as Azure Virtual Machines, Azure Virtual Desktop, and on-premises virtual machines hosted on Citrix or Hyper-V— it’s recommended to apply the out-of-band update (KB5062170) instead.

Steps to recover your device

If you experienced this issue and are unable to start Windows, try the following steps to recover your device. After you've recovered your device, install the out-of-band update (KB5062170) via the Microsoft Update Catalog.

On Recovery-enabled devices:

1. Access the Windows Recovery Environment.

2. Restart Windows.

On non-Recovery enabled devices:

1. Mount the virtual hard disk (VHD) from a remote device.

2. Mount the VHD on another virtual machine (VM) or device as a data disk and then return it back to the affected VM.

3. Restart Windows in normal mode. This will revert Windows to the last successfully installed Windows update.

For Azure customers who have already applied the update and are experiencing issues, see the self-help repair steps outlined in Repair a Windows VM using Azure Virtual Machine repair commands.