Microsoft has unveiled the latest iteration of its Windows Server build, designated as 26311, for participants in the Windows Server Insider Program. This release marks a significant milestone as it adopts the Windows Server 2025 branding, setting the stage for future developments in the server landscape.
New Features and Enhancements
Interestingly, the change log accompanying build 26311 mirrors that of its predecessor, build 26304. The earlier version introduced a noteworthy enhancement: the Windows Defender Application Control for Business (WDAC). This feature is designed to bolster security measures within Windows Server 2025 by establishing a defined list of authorized software, thereby minimizing potential attack vectors.
The key highlights of the change log for Windows Server 2025 preview build 26311 include:
What’s New
[NEW] Windows Defender Application Control for Business (WDAC)
WDAC serves as a robust security layer that enforces a strict list of permissible software. For Windows Server 2025, Microsoft has provided a ‘default policy’ that can be implemented via PowerShell cmdlets, utilizing the ‘OSconfig’ security configuration platform. For further details, users are encouraged to explore the Microsoft Community Hub.
Windows Server 2025 Security Baseline Preview
Starting with build 26296, Microsoft has introduced the Windows Server 2025 Security Baseline Preview. This feature allows users to establish a secure environment from the outset by applying a tailored security baseline, which encompasses over 350 preconfigured Windows security settings. These settings are organized into three categories based on server roles:
- Domain Controller (DC)
- Member Server
- Workgroup Member
Note: It is advisable to test the security baseline exclusively on non-production systems, as not all configurations can be reversed. More information can be found on the Microsoft Community Hub.
Windows Server Flighting
For those enrolled in Server Flighting, the new build will be automatically delivered later today. Additional insights are available in the Windows Insider flighting on Windows Server documentation.
The updated Feedback Hub app is now accessible for Server Desktop users. It should update automatically, but users can manually check for updates in the app’s settings if necessary.
Known Issues
As with any new release, there are some known issues to be aware of:
- Flighting: The label for this flight may mistakenly indicate Windows 11. However, users should proceed with the installation as it pertains to the Windows Server update.
- WinPE – PowerShell Scripts: The installation of the WinPE-PowerShell optional component may not function correctly, leading to failures in PowerShell cmdlets. Users reliant on PowerShell in WinPE are advised against using this build.
- For those validating upgrades from Windows Server 2019 or 2022, it is recommended to avoid this build due to identified intermittent upgrade failures.
- An issue exists where archiving event logs using the “wevetutil al” command may cause the Windows Event Log service to crash, necessitating a restart of the service via “Start-Service EventLog” from an administrative command prompt.
- If Secure Launch/DRTM code path is enabled, installation of this build is not recommended.
Available Downloads
Users should note that downloads may not be accessible in certain regions, particularly in light of Microsoft’s suspension of new sales in Russia. The following downloads are available:
- Windows Server Long-Term Servicing Channel Preview in ISO format across 18 languages, and in VHDX format in English only.
- Windows Server Datacenter Azure Edition Preview in both ISO and VHDX formats, available in English only.
- Microsoft Server Languages and Optional Features Preview
Keys: The keys provided are valid solely for preview builds:
- Server Standard: MFY9F-XBN2F-TYFMP-CCV49-RMYVH
- Datacenter: 2KNJJ-33Y9H-2GXGX-KMQWH-G6H67
- Azure Edition does not require a key.
Symbols: Available on the public symbol server – see Using the Microsoft Symbol Server.
Expiration: This Windows Server Preview is set to expire on September 15, 2025.
For those eager to explore the new Windows Server preview, downloads are available directly from Microsoft’s official site.
