404 Tech Support

Use Remote Desktop to Control a Current Session

This is for Windows XP Professional and Windows Server 2003. If you want to use Remote Desktop to control a session already logged in at the console (physically at and logged into the machine) instead of starting a new session (Windows Server 2003 default) or kicking off the current user (Windows XP default), use the following commands to achieve this.

Problem: I am logged into my machine in my office and have something open I want to get to from another computer in the building, on the network, or VPN’d in from off the network. If I use Remote Desktop, I just get another session on my Windows Server 2003 machine and still don’t get access to what I need. (If it were just a saved file, I could get to it through a file share.) Further more, if I have Firefox and Thunderbird open in my console session, I can’t start them up remotely because of the error: “Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.” (or substitute ‘Thunderbird’ in for ‘Firefox’ in that error message).

Possible solution: Install a VNC server on the machine and use that to connect. This requires a VNC viewer installed on all the machines I might be connecting from and another process on my machine to secure and be running at all times.

Real solution: Using Windows Remote Desktop there are switches that allow you to interact with the console session rather than starting a new one. The switch depends on what operating system you are connecting from, and is independent of which operating system you’re connecting to.

From Windows XP Pro: At Start, Run… enter: mstsc /admin
Or change the target field in a shortcut to be mstsc.exe /admin

From Windows Server 2003: At Start, Run… enter mstsc /console
Or change the target field in a shortcut to be mstsc.exe /console

Remote Desktop shortcut properties

Some notes on behavior:
+ Whether you’re connecting to XP or Server 2003, the machine you’re connecting to will lock and hide what you’re doing from anyone that might be watching the local machine.

+ An odd little quirk I’ve noticed is that you can’t have both an interactive session of Remote Desktop running and a VNC session running. Not sure why at this point. Video mirror drivers? TCP ports conflicting?

+ For Windows XP, you can only interact with your own sessions. If you try logging in as another user, it will give you the following error message:
The user {username} is currently logged on to this computer. If you continue this user’s Windows Session will end and any un-saved data will be lost. Do you want to continue?

+ For Windows Server 2003, you can only interact with your own sessions by default, like above, but you can change this behavior. *You only need to do this if you are going to want to interact with console sessions of a different user name logged into the machine than your own, or what user name you’re logging into with Remote Desktop.*
Go to Start, Run…
Enter: mmc
Go to File, Add/Remove Snap-ins…

Click the Add button.

Scroll down to find ‘Terminal Services Configuration’. Click the ‘Add’ button and then click ‘Close’.

You should now see the Terminal Services Configuration listed. Expand Terminal Services Configuration and double-click on the Connections folder to open it.

In the right-side pane, you’ll see below. Right-click on the RDP-Tcp connection and go to Properties.

Click to the ‘Remote Control’ tab and configure it behave how you want it; whether you want to be able to interact or just view any console sessions on this machine and whether you want to require the user’s permission to grant access.

Of course, also check under the Permissions tab to make sure access is granted to those you want to be able to Remote Desktop into this local machine. Hit the OK button when everything is configured how you want it.

These settings can also be configured via the Group Policy Object Editor.

User ConfigurationAdministrative TemplatesTerminal ServicesSet rules for remote control of Terminal Services user sessions
-Allows you to configure View the session or interact with the session and require/don’t require the user’s permission.

Computer ConfigurationAdministrative TemplatesTerminal Services

-Contains a lot more generic settings related to Remote Desktop behavior.

Update: Windows Server 2008 uses the same switch as Windows XP Pro: mstsc /admin

Feeback is always welcome: I’m particularly interested in hearing how this behaves in Windows Vista and Windows Server 2008. Different switches? Different behaviors? Please post in the comments so that others might benefit.