C ++ overriding due to including header files multiple times

As the title says. I am facing override errors due to including header files multiple times. I know it because of this, but I don't know how to solve it. Yes, I previously posted the same issue on SO an hour in advance. But I couldn't explain correctly (I think so) and didn't get the expected answers. Here is the link:

C ++ Override Header Files

I am not editing this question as it was filled in :).

Ok, I have several classes and their structure looks like this:

main.cpp:

#include "Server.h"
#include "Handler.h"
#include "Processor.h"

int main(int argc, char* argv[])
{

}

      

        
        
        
      

    

server.h:

// Server.h
#pragma once

#include <winsock2.h>

      

        
        
        
      

    

Handler.h:

// Handler.h
#pragma once

#include <string>
#include <vector>

#include "Server.h"

      

        
        
        
      

    

Processor.cpp:

// Processor.cpp

#include "StdAfx.h"
#include "Processor.h"
#include "Handler.h"

      

        
        
        
      

    

server.cpp:

// Server.cpp

#include "Server.h"
#include "Processor.h"

      

        
        
        
      

    

The problem is that it <winsock2.h>

turns on several times, I don't know where it is. # pragma does the same task once as

#ifndef SOME_FILE_H
#define SOME_FILE_H
// code here
#endif // SOME_FILE_H

      

        
        
        
      

    

in my compiler (MSVC2008 in this case). So I'm pretty sure I don't need a heading that includes guards. But can you determine where I am making the mistake that <winsock2.>

turns on twice and how can I solve?

thank