ERROR?

I keep getting this error:

post it i'll help you

#ifndef _WINDOWS_
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <string>
#include <fstream>

using namespace std;

class CSignatureSearch{

private:
int Match(BYTE* bComparison, BYTE* bSignature, int nSize, BYTE bWildCard);

public:
CSignatureSearch();
~CSignatureSearch();

DWORD SigSearch(DWORD dwStartAddress, DWORD dwEndAddress, BYTE* bSignature, int nSize, BYTE bWildCard);
string CreateSignature(DWORD dwAddress);
};
#endif