In Windows Server 2012, you can do most, if not all administrative tasks using Powershell. There are roughly 2400 comdlets letting you manipulate the system in every unholy way imaginable! One of those ways is to change the computer name.
To change the computer name, simply run the following two lines:
$system = GetWmiObject -Class Win32_ComputerSystem
You can for example use this code to script renaming multiple computers in bulk, or just to avoid cluttering up your screen with a GUI.