Your computer could not connect to another console session on the remote computer because you already have a console session in progress.

You can use port tester to verify if computer you are connecting has Remote desctop service available.
1.Download porttester unzip and run (no installation required).
2.Specify computer name and port 3389 (RDP port)
If it will return "Port unavailable" that means there is no physical connection to remote
desktop service on target computer.

what is port ?

< Imagine server like big socket board and every physical socket has number. So port is just a number of this socket.
Historically major part of standard services working on predefined ports like:

http:80

https:443

So in order to check if server has service running it's good enough to check if port is accessible.

yahoo messenger port number

There are different yahoo servers (server farm ?) but there are using same port 5050:
cs215p4.msg.sp1.yahoo.com:5050
cs216p2.msg.sp1.yahoo.com:5050
cs214.msg.sp1.yahoo.com:5050

check if sql server is running

To check if SQL server is available for your computer,
you can use port-tester and check connection to port 1433.
If it's returning port available that means sql server is up and running

port availability checker

I'm using this simple port testing software to check port:

I was thinking of adding ports listing and complete port dictionary to the application , byt I think
it's good how it is :) without having large lists of ports and and helps.

msn messenger port

As far as i know it has two types of connections:
And can be connected to : messenger.hotmail.com 1863 or
gateway.messenger.hotmail.com 80
And of cource you can use porttester to check if msn messager is available from your network

check tcp port availability

Port Tester

I need tool for testing port availability on client's server.
So I decided to write  port test  utility to verify availability of client's server.
This is beta version,provided "as is" with absolutely no warranty and responsibility.

It requires to have .Net 2.0 installed.And no installation required.
Port Tester Utility Download