Reading and Writing from Windows Registry

The following is an example of reading and writing from Windows Registry using C++. The code have been created based on examples from MSDN. I have provided the MSDN references in the code in case you want to lookup the documentation.

//Program tested on Microsoft Visual Studio 2008 - Zahid Ghadialy
//This program shows example of reading and writing from registry
#include <windows.h>
#include <iostream>

using namespace std;

#define WIN_32_LEAN_AND_MEAN

void writeToRegistry(void)
{
  DWORD lRv;
  HKEY hKey;

  //Check if the registry exists
  //http://msdn.microsoft.com/en-us/library/ms724897(VS.85).aspx
  lRv = RegOpenKeyEx(
    HKEY_CURRENT_USER,
    L"Software\\Zahid",
    0,
    KEY_WRITE,
    &hKey
  );

  if (lRv != ERROR_SUCCESS)
  {
    DWORD dwDisposition;

    // Create a key if it did not exist
    //http://msdn.microsoft.com/en-us/library/ms724844(VS.85).aspx
    lRv = RegCreateKeyEx(
      HKEY_CURRENT_USER,
      L"Software\\Zahid", //"Use Multi-Byte Character Set" by using L
      0,
      NULL,
      REG_OPTION_NON_VOLATILE,
      KEY_ALL_ACCESS,
      NULL,
      &hKey,
      &dwDisposition
    );

    DWORD dwValue = 1;

    //http://msdn.microsoft.com/en-us/library/ms724923(VS.85).aspx
    RegSetValueEx(
      hKey,
      L"Something",
      0,
      REG_DWORD,
      reinterpret_cast<BYTE *>(&dwValue),
      sizeof(dwValue)
    );

    //http://msdn.microsoft.com/en-us/library/ms724837(VS.85).aspx
    RegCloseKey(hKey);
  }
}

void readValueFromRegistry(void)
{
  //Example from http://msdn.microsoft.com/en-us/library/ms724911(VS.85).aspx

  HKEY hKey;

  //Check if the registry exists
  DWORD lRv = RegOpenKeyEx(
    HKEY_CURRENT_USER,
    L"Software\\Zahid",
    0,
    KEY_READ,
    &hKey
  );

  if (lRv == ERROR_SUCCESS)
  {
    DWORD BufferSize = sizeof(DWORD);
    DWORD dwRet;
    DWORD cbData;
    DWORD cbVal = 0;

    dwRet = RegQueryValueEx(
      hKey,
      L"Something",
      NULL,
      NULL,
      (LPBYTE)&cbVal,
      &cbData
    );

    if( dwRet == ERROR_SUCCESS )
      cout<<"\nValue of Something is " << cbVal << endl;
    else cout<<"\nRegQueryValueEx failed " << dwRet << endl;
  }
  else
  {
    cout<<"RegOpenKeyEx failed " << lRv << endl;
  }
}

int main()
{
  writeToRegistry();
  readValueFromRegistry();
  return 0;
}

The output is as follows: