How to open port in the windows firewall, (windows server 2003 - all blocked by default / windows XP all blocked by default)
look at the network conection.
right click select properties.
go to the advanced tab.
click settings
(windows firewall dialogue appears)
click the advanced tab.
select the network connection you want, (if there are more than one)
click settings.
click add
fill in the description of service box.
then fill in the local name or address of the computer in the computers hosting box
the fill in the internal and external ports...
(of course this rather misses to point)
when a connection is made outgoing, ie
your computer -> steam server
a reply port is opened by the server, the reply port is usually random, and above 1024, so you see if you can contact the steam server then you should be able to recieve a reply.
if you are finding that the steam server still can't be contacted it could be that either the windows server 2003 machine (I assume is a gateway) is blocking the connection, or your local machine is blocking the connection.
and way,
go back to the windows firewal (on the local machine)
change from the advanced tab to the exceptpions tab, add the program that is trying to contact steam servers to the list of exceptions.
hopefully that should sort it.