Socket Programming help

So I made a server and a client in C# using sockets. when i run both the client and the server on the same machine it connects. but if i run the server on my machine and the client on someone else's machine on different networks, it won't connect :/ Basically all the program does is say "Connected" if the server and client make a connection. does anyone have any ideas on how to make it work? Thanks!

1- Make sure you are using correct IP's (Not localhost or 127.0.0.1)
2- Make sure that the server has the port which receives the connection open
3- No Firewall blocking..
4- Profit??

1- i checked the corrected IP is used.
2- "TcpListener tcplistener = new TcpListener(IPAddress.Any, 9572);" that opens the server on port 9572 and accepts any IPAddress. right?
3- How would i know?
4- As of now no but i have been thinking 'bout it so probably in the near future. why?

if you are behind a firewall or a port blocked (Router) which is blocking your outside connections, you never reach the server...

how do i change firewall settings on Windows 7? i'm still getting used to it so i don't know yet! Thanks

go ahead : How to Use Windows 7 Firewall

its not necessarily your windows firewall.. but might be router one too. (and ports, don't ignore this...)

open cmd and type in:
IPCONFIG

Find your Default Gateway, and then paste ur gateway on the browser's url tab...
Your default gateway should be:
and the username & password: admin
Then you have to forward the port manually.

Edit:
I made a vid to forward ports sometimes ago.. It's for Modern Warfare 2, but the way is the same, you have only to change the port number...