#include <cstdlib>
#include <iostream>
#include "windows.h"
#include "winnt.h"
#include "winreg.h"
 
 
using namespace std;
 
int main(int argc, char *argv[])
{
    HKEY myKey = 0;
 
    char szValueBuff[255] = {0};
    char szValueName[255] = {0};
 
    DWORD dwType = REG_SZ;
 
    if(RegOpenKey(HKEY_CURRENT_USER, "Software\\Microsoft\\Windows NT\\CurrentVersion\\Winlogon", &myKey) == ERROR_SUCCESS)
    {
       cout << "Windows is installed!(Duh!)\n";
 
       DWORD index = 0;
       DWORD dwValueNameSize = sizeof(szValueName);
       DWORD dwValueBuffSize = sizeof(szValueBuff);
       while(RegEnumValue(myKey, index, szValueName, &dwValueNameSize, 0,
       &dwType, (byte *)szValueBuff, &dwValueBuffSize) == ERROR_SUCCESS)
	   {
			 cout << szValueName << " : " << szValueBuff << "\n";
			 index++;
	   }
 
       cout << "Error - ";
	   cout << RegEnumValue(myKey, index, szValueName, &dwValueNameSize, 0,
	   &dwType, (byte *)szValueBuff, &dwValueBuffSize);
	   cout << '\n';
 
       RegCloseKey(myKey);
    }
 
    system("PAUSE");
    return EXIT_SUCCESS;
}

Windows is installed!(Duh!)
ParseAutoexec : 1
Error - 234
Press any key to continue . . .