RDP: You are already connected to the Console of this computer.

This did not work.  I tried "mstsc /v:SERVERNAME" in the the run menu and I recieve the same error message.  I also was not able to locate the "reconnect to the same session" setting.  Also when I log into the server directly, and check terminal services for the sessions, there are no RDP session listed.  There is one Console session (which is the session I just logged on with at the server itself).  Any other ideas? I can also connect from this computer to other Windows 2003 servers.  I am only having trouble with our Domain Controller.

Also, I do not know if this makes a difference, but I canot connect from my XP machine to the Server machine using any username.  Even if I purposefully put in an incorrect password, it does not try to connect.  As I have looked into this error message, it typically points to the fact that the RDP session is attempting to connect to the computer it is originating from.  I know I am inputing the correct information, but could there be something else wrong somewhere that would cause a loopback in RDP?

I just checked from another computer and another username, and they recieve the same message too. Is there possibly a service that is not set up?  Also, we have just installed the Microsoft Firewall Client  Manager on both of these systems, could this influence the error?

If all else fails.....have you tried re-booting the server?

The Windows firewall will definitely block connections, but you would usually get a different error. Might want to double check that. "Usually" by default remote desktop will add an exception to the Windows firewall automatically., but that is when it is enabled after the firewall. Regardless, the firewall will usually have an exception for remote desktop but only from the same subnet. I would review the firewall settings;
Control panel | windows firewall | exceptions | make sure remote desktop is checked | highlight remote desktop and choose edit | highlight 3389 and choose scope options | adjust accordingly

>>"....that would cause a loopback in RDP? >
Very odd, I haven't run into that.

By the way the new RD client when connecting to 2003 servers requires you add the domain name to the user name such as:
DomainName\UserName

Ok, I have narrowed it down to an ISA issue.  I just am not sure what needs to be changed in our ISA Server (which resides on the domain server than I am having trouple accessing)  We have a web proxy set up.  In order to access a few POP3 accounts and other internet tools, we have Direct Access enabled to a few domains.  In order to use the Direct access, the Microsoft Firewall Client Manager was installed.  The computers that have the firewall client installed are those that cannot RDP into ISA/Domain server.  Any idea on what needs to be changed in ISA?  we have the default TS/RDP rules in place and enabled, and RDP protocols allowed.

>>"Is there possibly a service that is not set up?  "
Yes, but the error would be different.....usually.
Verify the terminal Services service must be running
If you have access to the remote machine make sure it is "listening" for your connection. To do so at a command line enter (substitute port # if not using default 3389):
  netstat  -an  |find  "3389"
You should get the following result:
TCP   0.0.0.0:3389    0.0.0.0:0    listening
or you can just enter:
   netstat  -an
and search for 3389 listening

Sorry ISA is not my field. Have only worked with it briefly, but that could easily explain the blocked connection.

OK, well, I am certain this is an issue with ISA.  In the logfile for the firewall is is passing it through, however it is first changed from the originating host name to "localhost". I am not sure what is changing that information from what the hostname/address should be, but by the time the listener at port 3389 receives the request is sees "localhost" as the originator and thinks it is supposed to connect to itself, at which point the error message is sent back.  If you do not have no idea how to solve this, then I will go agead and award you the points for your help and post an ISA server question.  Thanks!

Definitely sounds like ISA. There are some great ISA guys around. You can post a pointer question to this one in another topic area if you like to draw the attention of one of those persons.
http://www.experts-exchange.com/help.jsp#hi262

You propably downloaded the RDP update.
I am facing this same problem.
You can either uninstall the version 6 and go back to the old version...
or, when you want to connect disable firewall client then connect, then re-enable it again.

Hope that helps.

Same thing is happening to me, except it's only on one PC.

I can confirm that disabling the firewall client allows access to the server.

I had the same error, but probably for different reasons. Basically I am dynamically assigning my internal ip's. The server is always on, so I don't worry about it being assigned a different ip, this rarely happens. Today the power went out and a new internal ip address was assigned. I updated my firewall rule and forgot to edit the RDP shortcut with the new ip. The error i received really had nothing to do with the actual problem. Changing 192.168.1.100 to 192.168.1.101 fixed my problem.

I also have the same issue but -
FW on server is not the issue..
I am configured NOT to use our ISA server so this is not the issue..
Just started happening one morning..
No updates have been installed so this is not the issue..
Back tracking I have identified NO updates or CHANGES were completed on servers with this issue.
I have noticed this is now happening on more then one server also.. very weird.. got to love MS :(

oh and only way I can connect is to RDC on to a server allowing RDC connections and then from there RDC onto the correct server.. FYI I am in one domain and the servers are in another at my Datacenter, yes the trusts seem to be fine for the domains.

Right this issue is due to the MS update for RDC and that its VERY broken... if you remove the update for RDC to go back to version 5.1 then all is resolved.. this issue is on the client and not server!

I agree with RobWill regarding the quality of the latest RDP.  My issue was due to the machine I was attempting to RDP into was our ISA 2000 server running web proxy.  In order to make better use of the web proxy i had installed Microsoft Firewall Client on the local machine.  If I disable the Firewall Client that connects me to the ISA server, the problem does not occur and RDP works flawlessly.

I appologize for not posting and closing this question earlier.  Thank you RobWill for your persistence.