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 2013-06-25 through MSDN (screenshot). Later on, it became publicly available through Microsoft Technet Evaluation Center. First, it was thought to be released alongside the client build at BUILD 2013 on 2013-06-26, but it came a day earlier. On the same day, System Center 2012 R2 Preview was also released. It is the first leaked build of Server 2012 R2 to have the new start button.