SocketException prevents C # TCPListener from being used on Windows Service

I have a windows service that does the following when it starts. When run through a console application, it works fine, but as soon as I put the windows service, I get the following exception. Here's what I've tried so far:

• Disabled firewall, also tried to add explicit exceptions for exe, port and protocol
• Verified CAS Policy Config, Shows Unlimited Rights
• Configuring the service to run as an administrator account, local system, local service, and network service, each with the same result
• Tried different ports
• Also tried 127.0.0.1 just to look ... same thread

This is ruining my head, so any help would be greatly appreciated:

The code:

var _listener = new TcpListener(endpoint); //192.168.2.2:20000
_listener.Start();

      

        
        
        
      

    

Received exception:

Service cannot be started. System.Net.Sockets.SocketException: An attempt was made to access a socket in a way forbidden by its access permissions
   at System.Net.Sockets.Socket.DoBind(EndPoint endPointSnapshot, SocketAddress socketAddress)
   at System.Net.Sockets.Socket.Bind(EndPoint localEP)
   at System.Net.Sockets.TcpListener.Start(Int32 backlog)
   at System.Net.Sockets.TcpListener.Start()
   at Server.RequestHandler.StartServicingRequests(IPEndPoint endpoint)
   at Server.Server.StartServer(String[] args)
   at Server.Server.OnStart(String[] args)
   at System.ServiceProcess.ServiceBase.ServiceQueuedMainCallback(Object state)