I receive sometimes the following message when attempting to start a new Remote Desktop Session onto a Windows 2003 server.

 The terminal server has exceeded the maximum number of allowed connections

 If you are on a client machine and logged on as a domain Admin, the the following command from the command prompt will display users:

qwinsta /server:SERVERIP

 Replace SERVERIP with either ipaddress (or domain name) of the Remote Server

 An example :

 qwinsta /server:PIRANHA

 You’ll see a list of users with various states

SESSIONNAME       USERNAME                 ID  STATE   TYPE        DEVICE

Rdp-tcp#47                  user1                          4    conn        rdpwd

Rdp-tcp#48                  user2                          5    Active        rdpwd

To disconnect  a remote session use the command:

rwinsta /server:SERVERIP SESSIONID

Replace SESSIONID with the ID – so extending our example , to disconnect the second listed user do :

rwinsta /server:PIRANHA 5

Ref:Jack Vamvas (http://www.sqlserver-dba.com)