Hello again,
The exception error is the following:
java.net.ConnectException:Connection refused: connect

The code of my program is the following:
MyServer.java
//The following program has the server sending a String to the client
//using the DataOutputStream class

//Demonstrates a ServerSocket listening for requests

//The server uses the SeverSocket class to grab a port and listen
//for requests

import java.io.*;
import java.net.*;

public class MyServer implements Runnable
{
ServerSocket server;
Socket client;

public MyServer(int port) throws IOException
{
server= new ServerSocket(port);
}

public void run()
{
    while (true)
    {
    try {
//communicate with client, then close the connection
    client=server.accept();
    System.out.println("Made one connection");
    OutputStream clientOutputStream=client.getOutputStream();
    DataOutputStream out=new DataOutputStream(clientOutputStream);
    out.writeUTF("Hello from " + server.getInetAddress());

    clientOutputStream.close();
    client.close();

} catch (IOException e) {
System.out.println(e);
return;
}

}
}

}

The code of MyServerProgram is:

import java.io.*;

public class MyServerProgram
{
public static void main(String [] args)
{
try {
MyServer server=new MyServer(5000);

Thread t=new Thread(server);
t.start();
System.out.println("Server is ready for a client");

} catch (IOException e) {
e.printStackTrace();
}

}

}

And finally the code of MyClient program is:
//The client uses the Socket class to connect to a server.The
constructor
//needs the name of the server and the port to connect to

//The following program demonstrates a client connecting to the server
//in the earlier example.
//The client will read in the String sent from the server by using the
//DataInputStream class

import java.io.*;
import java.net.*;

public class MyClient
{
public static void main(String[] args)
{
String server="localhost";
//args[0];
int port=5000;
//Integer.parseInt(args[1]);

try
{
Socket host=new Socket(server,port);
//System.out.println("Connected to " +
//    host.getInetAddress() );

//InputStream serverInStream=host.getInputStream();
//DataInputStream in=new DataInputStream(serverInStream);
//System.out.println(in.readUTF());

//serverInStream.close();
//communicate with the server, then close the socket
host.close();
} catch (IOException e) {
System.out.println(e);
}

}

}

Many Thanks
Dora

Hello again,
I do not know what it means firewall software. However, I have recently
instaleed the Norton Antivirus; would that make any difference?
I run the MyServerProgram and the MyClient programs in two MS-DOS
windows.

Secondly, the use of 127.0.0.1 as server string instead of localhost
does not make any difference and the same exception is thrown.

Thanks
Dora