Windows XP
Go to your Control Panel. Double click on System. Under Remote tab, tick to enable or un-tick to disable the remote desktop connection.
Windows Server 2012
In Windows Server 2012, open the Server Manager and click on Local Server. By default, the remote desktop connection is disabled. To enable or disable, click on the link next to Remote Desktop.
In the System Properties, select Allow remote connections to this computer to enable. If disable, select Don’t allow remote connections to this computer.
