When windows firewall on

I can't connect to it(Server) on other PC. = =||
It took me 2 hours.


using (TcpClient server = new TcpClient(serverIP, cmd.Port)) {
using (NetworkStream ns = server.GetStream()) {
using (StreamWriter Writer = new StreamWriter(ns, Encoding.UTF8)) {
string strJson = JsonConvert.SerializeObject(cmd, Formatting.Indented);
Writer.Write(strJson);

}
//ns.Close();
}
//server.Close();
}