Unknown Error while Socket Programming

[escap3]

hey, how're you !?
buddies, I had a problem while creating a sample application which I recently downloaded from Micorosoft MSDN online library ...
here's is the picture of application :
http://www.turboimagehost.com/p/1817487/Error.JPG.html
and this is the source code :

using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.Net.Sockets;
namespace Socket_Baseed_Application
{
class Program
{
static void Main(string[] args)
{
Console.ForegroundColor = ConsoleColor.Green;
TcpListener server = null;
try
{
Int32 port = 3333;
IPAddress localAddr = IPAddress.Parse("127.0.0.1");
server = new TcpListener(localAddr, port);
server.Start();
Byte[] bytes = new Byte[256];
string data = null;
while (true)
{
Console.WriteLine("waiting for a connection");
TcpClient client = server.AcceptTcpClient();
Console.WriteLine("Connected !");
data = null;
NetworkStream stream = client.GetStream();
int i;
while ((i=stream.Read(bytes,0,bytes.Length))!=0)
{
data = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
Console.WriteLine("Recieved : {0}",data);
data = data.ToUpper();
byte[] msg = System.Text.Encoding.ASCII.GetBytes(data);
stream.Write(msg, 0, msg.Length);
Console.WriteLine("Sent : {0}",data);
}
client.Close();
}

}
catch (SocketException e)
{
Console.WriteLine("Socket Exception : {0}", e);
}
finally
{
server.Stop();
}
Console.WriteLine("\nHit enter to continue ...");
Console.Read();

}
}
}



I will really appreciate to one who can help me ...
unfortunately, every application that I create with this class has the same problem ...,

beforehand appreciate ...
thanks .

[BigEd781]

The error message says very clearly that

"The requested service provider could not be loade4d or initialized"

That error is occurring in the Socket class constructor.

[escap3]

give me a right way please, how can I solve this problem !?