The all new Windows Server 2012 Server Manager is an amazing tool to manage not only the server you are on, but also remotely control other servers on the network. Once you have your servers all configured, you may not want Server Manager to start every time you connect to your server and eat up resources, there is an easy way to disable it from auto start.
Launch Server Manager from the task bar if it is not already up.
On the top right hand side of server manager, click on Manage, then go to Server Manager Properties
In Server Manager Properties window, check the box “Do not start Server Manager automatically at logon” then click OK
Server Manager will not start automatically anymore. You can always go back and un-check the same box to reverse the process.