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