Microsoft has released the latest Windows Server build for members of the Windows Server Insider Program. The new build number is 26311. Keep in mind that this and future Windows Server Insider builds now have the Windows Server 2025 branding.
Unfortunately, the official change log that Microsoft published for Windows Server 2025 preview build 26311 is identical to the change log that was published with the last preview build, which had the version number 26304. That previous build added a major new feature, the Windows Defender Application Control for Business (WDAC), which adds some new security features for Windows Server 2025.
Keeping all that in mind, here is the published change log for Windows Server 2025 preview build 26311:
What"s New
[NEW] Windows Defender Application Control for Business (WDAC)
Windows Defender Application Control (WDAC) for business is a software-based security layer that reduces attack surface by enforcing an explicit list of software that is allowed to run. For Windows Server 2025, we have provided Microsoft defined ‘default policy’ which can be applied to the server via PowerShell cmdlets, powered by our ‘Security configuration platform called ‘OSconfig’. To learn more, please review Windows Defender Application Control for Business (WDAC) - Microsoft Community Hub.
Windows Server 2025 Security Baseline Preview
Beginning with build 26296, we are pleased to announce the availability of the Windows Server 2025 Security Baseline Preview. You can enable security right from the start by applying the recommended security posture for your device or VM role through application of a tailored security baseline, with over 350 preconfigured Windows security settings that help you apply and enforce granular security settings that support best practices recommended by Microsoft and Industry standards. We have organized the Windows Server 2025 Security Baseline content into three categories based on server role:
- Domain Controller (DC)
- Member Server
- Workgroup Member
Note: You should preview the security baseline only on test systems. While there is a ‘Remove’ command, not all configurations can be reversed. To learn more, please review Announcing Windows Server 2025 Security Baseline Preview - Microsoft Community Hub.
Windows Server Flighting is here!!
If you signed up for Server Flighting, you should receive this new build automatically later today. For more information, see Welcome to Windows Insider flighting on Windows Server - Microsoft Community Hub
The new Feedback Hub app is now available for Server Desktop users! The app should automatically update with the latest version, but if it does not, simply Check for updates in the app’s settings tab.
Known Issues
Download Windows Server Insider Preview (microsoft.com)
Flighting: The label for this flight may incorrectly reference Windows 11. However, when selected, the package installed is the Windows Server update. Please ignore the label and proceed with installing your flight. This issue will be addressed in a future release.
WinPE - Powershell Scripts: Applying the WinPE-Powershell optional component does not properly install Powershell in WinPE. As a result, Powershell cmdlets will fail. Customers who are dependent on Powershell in WinPE should not use this build.
If you are validating upgrades from Windows Server 2019 or 2022, we do not recommend that you use this build as intermittent upgrade failures have been identified for this build.
This build has an issue where archiving eventlogs with "wevetutil al" command causes the Windows Event Log service to crash, and the archive operation to fail. The service must be restarted by executing "Start-Service EventLog" from an administrative command line prompt.
If you have Secure Launch/DRTM code path enabled, we do not recommend that you install this build.
Available Downloads
Downloads to certain countries may not be available. See Microsoft suspends new sales in Russia - Microsoft On the Issues.
- Windows Server Long-Term Servicing Channel Preview in ISO format in 18 languages, and in VHDX format in English only.
- Windows Server Datacenter Azure Edition Preview in ISO and VHDX format, English only.
- Microsoft Server Languages and Optional Features Preview
Keys: Keys are valid for preview builds only
- Server Standard: MFY9F-XBN2F-TYFMP-CCV49-RMYVH
- Datacenter: 2KNJJ-33Y9H-2GXGX-KMQWH-G6H67
- Azure Edition does not accept a key
Symbols: Available on the public symbol server – see Using the Microsoft Symbol Server.
Expiration: This Windows Server Preview will expire September 15, 2025.
You can download the new Windows Server preview from Microsoft"s site.