Thanks DJHyperbyte.

Yes, it is shared using ICS. But when I try to connect msn from the client computer it gives an error message that says
“We were unable to sign you into .NET messenger service, possibly because of a problem with the service or with your internet connection. Please make sure that you are connected to the internet..Click Help button to check the service status”:(

But I can connect from the server without any problem.

Any idea?