I am almost there. I have gotten to the point where I can now connect to the server. I have sent my flight plan and have everything up and running but when I push o.k. in the "connect to PC/SB server" window and try to connect I get an error message saying "the attempt to connect was forcefully rejected" and "your callsign was not found! you must log in on a VATSIM server before joining a voice server!"I have checked my call sign and it seems to be the same everwhere I can enter a call sign - LH401.

First of all have you looked through the extensive documents at http://www.vatsim.net/prc, it was set up to help new VATSIM members connect and use VATSIM?From your brief description it could be one of two problems.1) Your list of IP addresses for the VATSIM servers is out of date, see http://www.vatsim.net/prc for how to update the addresses.2) The second part of your post suggests the error occurs when you try to use the voice client AVC. If that is the case you need to do what it says :-), i.e. connect to a VATSIM authentication server before you can connect to a controller on voice.If that is where your error occurs open AVC and go to the 'Pilot Info' tab. There you enter your VATSIM PID and password and also there is a drop-down list of authentication servers. Select one of them, then go back to the connection tab and connect. This will authenticate you onto VATSIM and from there you can connect to a controller.That is a one-off operation, once authenticated you will not have to do it again, just use AVC to connect to any controller.HTH