ODBC ERROR 14 FAILED CONNECTION

I am trying to connect a XP workstation to a Windows SBS 2003 Server using an ODBC connection.

The server is Windows SBS 2003 Server, Service Pack 2, 2gb ram and 200gb disk with SQL 2000 Service pack 4.  The workstation is a 2gb & 100gb disk with Windows XP Proff with SP2.

When creating the ODBC name in the workstation, I use the "System DSN" Tab and also I use "With SQL Server authentication using..." instead of "With Windows NT authentication..." and in Client Configuration I use TCP/IP (I also tried it with "Name Pipes:" instead of TCP/IP).

 When clicking Next in order to connect, I get this error:


   Connection failed:
   SQLState: '01000'
   SQL Server Error: 14
   [Microsoft][ODBC SQL Server Driver][TCP/IP Sockets]ConnectionOpen (Invalid Instance()).
   Connection failed:
   SQLState: '08001'
   SQL Server Error: 14
   [Microsoft][ODBC SQL Server Driver][TCP/IP Sockets]Invalid connection.

I have search the experts-exchange and found a question ("SQL Server Login error when attempting ODBC connection") my exact error message, unfortunately I tried its recommendation but It didnt work.

However, I created an ODBC connection within the Server and works fine, I can connect to the SQL Instance; but I can't get the workstation to connect.

In addition, I also tried the following at the workstation:

1. Ping the ServerName, tested ok
2. Ping the server IP address, tested ok
3. In ODBC, in the "Create a New Data Source..", I place the server IP address, and still no connect
4. Tested command-line "Telnet ServerName 1433", to test the 1433 port but I get a blank screen
    (I dont know if I what result should give, just wanted to test the port 1433)
5. Verified that the server name and the machine name are the same; and they are
6. Disable all firewall in the server and in the workstation, still no connect
7. Disable all antivirus & antispyware on server & workstation, still no connect
8. Uninstalled SQL 2000, rebooted server, deleted all folders related to SQL2000 and reinstall a ;
    fresh SQL 2000 and still no connection
9. Also disconnected and reconnected the workstation to the domain.  The  workstation can enter
    the server, has access to everything, except to connecting the server's SQL instance thru
    the ODBC.  Tried also connecting the ODBC withou having the workstation being part of
    the domain
10. Tried connection with the computer not being in the domain; no good
11. Tried the ODBC with both User DSN and System DSN, no connection
12. Tried in the ODBC "Server Name", a server name with the following format
       [servername]\[instance name];
       example   SERVER\SQLINSTANCE
      ...still no connection
13. Also tried replacing the file "Dbnmpntw.dll" in the windows\system32 with a fresh on;
      still no connection
14. Last I tried to connect this workstations' ODBC to another server with the same configuration
     & SQL and works fine.  So I am inclined to think it may be the server.

In essence, this specific server does not permit a workstation to connect thru OBDC.  The workstation can log on to the server and use it resources, but I can't get it to connect theu ODBC.  I have tried diferent workstation and still no ODBC connection.  I have another server, and the sames workstations, do connect to THAT server with no problema thru ODBC.  There is someting with the server that prevents any workstation to connect thru ODBC.