http://blogs.technet.com/b/askds/archive/2012/09/20/windows-server-2012-shell-game.aspx

Adding Server Graphical Shell and Graphical Management Tools and Infrastructure

Install-WindowsFeature server-gui-mgmt-infra,server-gui-shell -source:wim:d:\sources\install.wim:2

Use 2 for standard and 4 for a datacenter edition and make sure D is the drive with the DVD with Windows Server 2012.