Microsoft recently released a new build, version 26311, in the Windows Server Insider Program for Windows Server 2025. Unfortunately, the preview does not contain new functionality.
The tech giant does not specify in its description what exactly is the purpose of build 26311 for Windows Server 2025, as it does not add any new features compared to the earlier preview version, build 26304.
WDAC and Security Baseline Preview
However, the previous build did introduce an important extension: Windows Defender Application Control for Business (WDAC). This feature adds several security features to Windows Server 2025.
WDAC is a software-based security layer that reduces the attack surface by establishing a list of permitted software to run on affected servers. For Windows Server 2025, Microsoft has developed a standard policy that can be applied to the server via PowerShell cmdlets. Microsoft’s OSconfig security configuration platform supports this.
Another previously introduced feature in preview build 26311 is the Windows Server 2025 Security Baseline Preview. This feature helps administrators configure security via a recommended security posture. It allows them to provide their physical servers or VMs with a customized security baseline based on over 350 preconfigured Windows security settings.
A default policy that administrators can install on servers via OSconfig and PowerShell cmdlets was also developed for this feature.
The latest build in the Insider program for Windows Server 2025 is now available for download through various channels. This version is not available in some countries, and the build’s lifetime runs through Sept. 15, 2025.