Windows Server 2012 R2 build 9431

Windows Server 2012 R2 build 9431 is the official preview build of Windows Server 2012 R2, also known as the Milestone Preview. This build was released on 25 June 2013 through MSDN and was later made publicly available through the Microsoft TechNet Evaluation Center. It was also additionally released in the form of a set of Repair Content Packages, which are used by  to repair an existing Windows installation, making it one of the few remaining server builds to be released with a 32-bit counterpart after support for the x86 architecture was dropped with the release of Windows Server 2008 R2.

It is the first available build of Server 2012 R2 to have the new start button.