When you try to connect to a Windows Server 2003 box using Remote Desktop Connection (mstsc), you get an error message that you can not connect; because the number of connection exceeded the limits.
The number of available connection sessions through Remote Desktop Connection are limited to two (active or disconnected), and inorder to connect an empty session must be available to you. One of the mistakes is to exist the Remote Desktop Connection tool by clicking the X at the top right corner; this will disconnect the session, however it will not terminate it. So be sure to exit the RDC by using the log off command.
You cannot use the /console switch to connect to the console session of a computer that is running Microsoft Windows 2000 Server.