RDP : Remote Administration changes /console to /admin

In Windows Server 2003, you can start the RDC client (mstsc.exe) with the /console switch to remotely connect to the physical console session on the server (also known as session 0). In Windows Server 2008, the /console switch has been deprecated. (For more information, see the “Why the /console switch is no longer needed” section of this article.) In Windows Server 2008, session 0 is a non-interactive session that is reserved for services.
You can use the new /admin switch to remotely connect to a Windows Server 2008-based server for administrative purposes. The /admin switch is introduced with RDC 6.1. RDC 6.1 is included with the following operating systems:
• Windows Server 2008

• Windows Vista Service Pack 1 (SP1)

• Windows XP Service Pack 3 (SP3)

RDC 6.1 does not support the /console switch. However, for backward compatibility, you can use the /admin switch to connect to the physical console session on a Windows Server 2003-based server. For example, to connect from a Windows Vista SP1 RC-based client to the physical console session of a Windows Server 2003-based server, you can run the command mstsc.exe /admin.
Want More Information about the /admin switch?
You can start the RDC 6.1 client (mstsc.exe) with the /admin switch to remotely administer a Windows Server 2008-based server (with or without Terminal Server installed). However, if you are connecting to remotely administer a Windows Server 2008-based server that does not have the Terminal Server role service installed, you do not have to specify the /admin switch. (In this case, the same connection behavior occurs with or without the /admin switch.) At any point in time, there can be two active remote administration sessions. To start a remote administration session, you must be a member of the Administrators group on the server to which you are connecting.
Behavior when you connect to a server that does not have Terminal Server installed
If you (as a member of the Administrators group on the destination server) start a Remote Desktop session to a Windows Server 2008-based server that does not have the Terminal Server role service installed, the following behavior is true for the remote administration session:
• Time zone redirection is disabled.

• Terminal Services Session Broker (TS Session Broker) redirection is disabled.

• Plug and Play device redirection is disabled.

• The remote session theme is changed to Windows Classic.

• Terminal Services Easy Print is disabled.

Behavior when you connect to a server that has Terminal Server installed
If you (as a member of the Administrators group on the destination server) start a Remote Desktop session to a Windows Server 2008-based server that has the Terminal Server role service installed, you must specify the /admin switch to connect to a session to remotely administer the server. The following behavior is true for the session:
• You do not need a TS CAL to connect remotely to administer a terminal server.

• Time zone redirection is disabled.

• Terminal Services Session Broker (TS Session Broker) redirection is disabled.

• Plug and Play device redirection is disabled.

• The remote session theme is changed to Windows Classic.

• Terminal Services Easy Print is disabled.