Microsoft has unveiled the latest build of Windows Server, designated as 26304, for participants in the Windows Server Insider Program. This release marks a significant milestone as it transitions to the Windows Server 2025 branding, setting the stage for future developments.
New Features and Enhancements
The standout feature of this release is the introduction of Windows Defender Application Control for Business (WDAC). This innovative security layer is designed to minimize the attack surface by enforcing a strict list of approved software. For Windows Server 2025, Microsoft has provided a predefined ‘default policy’ that can be easily implemented through PowerShell cmdlets, utilizing the robust ‘OSconfig’ security configuration platform. For further details, users can explore the Windows Defender Application Control for Business (WDAC) – Microsoft Community Hub.
Additionally, the Windows Server 2025 Security Baseline Preview is now available, allowing users to establish security measures right from the outset. This tailored security baseline comprises over 350 preconfigured settings that align with Microsoft’s best practices and industry standards. The content is categorized based on server roles:
- Domain Controller (DC)
- Member Server
- Workgroup Member
Note: It is advisable to preview the security baseline solely on test systems, as not all configurations can be reversed despite the presence of a ‘Remove’ command. For more information, visit the Announcing Windows Server 2025 Security Baseline Preview – Microsoft Community Hub.
Flighting and Feedback
For those who have opted into Server Flighting, the new build will be automatically delivered later today. More insights can be found in the Welcome to Windows Insider flighting on Windows Server – Microsoft Community Hub.
The updated Feedback Hub app is now accessible for Server Desktop users. It should automatically refresh to the latest version; however, users can manually check for updates in the app’s settings if necessary.
Known Issues
As with any new release, there are known issues to be aware of:
- Flighting: The label for this flight may mistakenly reference Windows 11. Nonetheless, the package installed will be the Windows Server update. Users are advised to disregard the label and proceed with the installation.
- WinPE – PowerShell Scripts: There is a malfunction when applying the WinPE-PowerShell optional component, leading to failures in PowerShell cmdlets. Users reliant on PowerShell in WinPE should refrain from using this build.
- If validating upgrades from Windows Server 2019 or 2022, it is recommended to avoid this build due to identified intermittent upgrade failures.
- Archiving event logs using the “wevetutil al” command may cause the Windows Event Log service to crash, necessitating a restart via “Start-Service EventLog” from an administrative command line prompt.
- Those with Secure Launch/DRTM code path enabled should not install this build.
Available Downloads
Downloads may be limited in certain regions, particularly as Microsoft has suspended new sales in Russia. The following previews 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 format, English only.
- Microsoft Server Languages and Optional Features Preview
Keys: The keys provided are valid exclusively for preview builds:
- Server Standard: MFY9F-XBN2F-TYFMP-CCV49-RMYVH
- Datacenter: 2KNJJ-33Y9H-2GXGX-KMQWH-G6H67
- Azure Edition does not require a key.
Expiration: This Windows Server Preview is set to expire on September 15, 2025.
For those interested, the new Windows Server preview can be downloaded from Microsoft’s official site, where additional details are also available.
