Microsoft Releases New Preview Build of Windows Server 2025
Microsoft has recently rolled out build version 26311 in the Windows Server Insider Program for Windows Server 2025. However, this preview does not introduce any new functionality.
The purpose of build 26311 remains unspecified, as it offers no additional features over the prior preview build, version 26304.
WDAC and Security Baseline Preview
The previous build did, however, introduce key security enhancements, including Windows Defender Application Control for Business (WDAC). WDAC is a software-based security layer that minimizes attack surfaces by defining a list of authorized software for affected servers. For Windows Server 2025, Microsoft has developed a standard WDAC policy that can be applied using PowerShell cmdlets, supported by the OSconfig security configuration platform.
Additionally, build 26311 includes the Windows Server 2025 Security Baseline Preview, which aids administrators in configuring security through a recommended security posture. This feature provides physical servers or VMs with a tailored security baseline using over 350 preconfigured Windows security settings. A default security policy, deployable via OSconfig and PowerShell cmdlets, was also created for this feature.
The latest Windows Server 2025 build in the Insider Program is now available for download through select channels, though access may be restricted in certain regions. This build remains active until September 15, 2025.