Win Update KB5064080 Windows 11 Cumulative Update Preview build 22631.5840 (23H2) - Aug. 26

UPDATE 9/09:

August 26, 2025 - KB5064080 (OS Build 22621.5840) Preview​

Windows Secure Boot certificate expiration

Important: Secure Boot certificates used by most Windows devices are set to expire starting in June 2026. This might affect the ability of certain personal and business devices to boot securely if not updated in time. To avoid disruption, we recommend reviewing the guidance and taking action to update certificates in advance. For details and preparation steps, see Windows Secure Boot certificate expiration and CA updates.

To learn more about Windows update terminology, see types of Windows updates and monthly quality update types. To find an overview, see the update history page for Windows 11, version 23H2.

Stay informed! Follow @WindowsUpdate for the latest updates from the Windows release health dashboard.

End of servicing

Starting June 26, 2025, Windows 11 version 22H2 (Enterprise and Education editions) will no longer receive non-security preview updates. However, monthly security updates will continue through October 14, 2025. After that date, this version will reach the end of servicing and will no longer receive security updates. To stay protected and up to date, we recommend you upgrade to the latest version of Windows 11.

Learn more

Highlights​

This non-security update includes quality improvements.

• [Windows Backup for Organizations] New! Windows Backup for Organizations is now generally available! Experience seamless device transitions with enterprise-grade backup and restore. Whether you're refreshing your organization’s devices, upgrading to Windows 11, or deploying AI-powered PCs, this solution helps sustain productivity with minimal disruption, ensuring business continuity and organizational resilience.
  
  
  

  Windows Backup for Organizations is now available on Windows 10 and Windows 11

  Windows IT Pro Blog: We’re excited to announce the general availability of Windows Backup for Organizations! This new feature allows your organization to seamlessly back up Windows 10 or Windows 11 settings and effortlessly restore them on a Microsoft Entra joined device. As of today, you can...

  www.elevenforum.com

Improvements​

Normal rollout​

Important: Use EKB KB5027397 to update to Windows 11, version 23H2.

This non-security update includes quality improvements. 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.

• [Copilot] Fixed: Improved the Copilot key’s reliability and resolved an issue that prevented users from restarting Copilot after using the key.
• [Country and Operator Settings Asset (COSA)] Fixed: This update brings profiles up to date for certain mobile operators.
• [Device management] Fixed: An issue where the removable storage policy didn’t correctly block external devices such as USB flash drives.
• [Family Safety] Fixed: An issue where the “Ask to Use” approval prompt didn’t appear when blocked apps were opened. With this fix, apps now show the expected approval prompt when Family Safety settings are enabled.
• [File Explorer]
  • Fixed: File Explorer might unexpectedly only display a single folder (for example, Desktop), rather than the expected content with recent files and more.
  • Fixed: Syncing more SharePoint sites to File Explorer might slow performance when navigating folders or opening the context menu. This can also affect how quickly files launch.
• [File sharing] Fixed: This update addresses an issue where accessing files on a Server Message Block (SMB) share over Quick UDP Internet Connections (QUIC) might result in unexpected delays.
• [File system] Fixed: This update addresses an issue in Resilient File System (ReFS) where enabling deduplication and compression simultaneously could occasionally cause the system to stop responding.
• [Input]
  • Fixed: This update addresses an issue where certain extended Unicode characters—such as rare Chinese symbols—appeared as blank spaces or incorrect symbols in Windows text boxes. The fix ensures these characters display correctly and maintains compliance with GB18030-2022 requirements.
  • Fixed: This update addresses an issue with the Chinese (Simplified) Input Method Editor (IME) where some extended characters appeared as empty boxes.
• [Narrator] Fixed: This update addresses an issue where Narrator incorrectly read the name of the Enhance Facial Recognition Protection checkbox under the Facial recognition (Windows Hello) setting.
• [Network connectivity] Fixed: This update addresses an issue where Wi-Fi might not reconnect automatically after a Group Policy update.
• [Remote Desktop] Fixed: An issue where cameras didn’t appear during remote sessions after being added or removed. Newly connected cameras were not recognized in Remote Desktop Services (RDS) environments

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

Windows 11 servicing stack update (KB5064743) - 22621.5973​

This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. Servicing stack updates (SSU) ensure that you have a robust and reliable servicing stack so that your devices can receive and install Microsoft updates. To learn more about SSUs, see Simplifying on-premises deployment of servicing stack updates.

Known issues in this update​

Microsoft is not currently aware of any issues with this update.

How to get this update​

Before you install this update

Microsoft combines the latest servicing stack update (SSU) for your operating system with the latest cumulative update (LCU). For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.

Install this update

To install this update, use one of the following Windows and Microsoft release channels.


If you want to remove the LCU

To remove the LCU after installing the combined SSU and LCU package, use the DISM/Remove-Package command line option with the LCU package name as the argument. You can find the package name by using this command: DISM /online /get-packages.

Running Windows Update Standalone Installer (wusa.exe) with the /uninstall switch on the combined package will not work because the combined package contains the SSU. You cannot remove the SSU from the system after installation.

File information

For a list of the files provided in this update, download the file information for cumulative update 5064080 .

For a list of the files provided in the servicing stack update, download the file information for the SSU (KB5064743) - versions 22621.5973.






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