Wow i am suprised i cant find this....

#include <windows.h>

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
  LPSTR lpCmdLine, int nCmdShow)
{
  MessageBox(NULL, "Goodbye, cruel world!", "Note", MB_OK | MB_SYSTEMMODAL);
  return 0;
}

and usually i have to add "stdafx.h"
but i always get the error error C2664: 'MessageBoxW' : cannot convert parameter 2 from 'const char [22]' to 'LPCWSTR'

please help me i am so frustrated and just want to get making games again.

#include <windows.h>

const char g_szClassName[] = "myWindowClass";

// Step 4: the Window Procedure
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
  switch(msg)
  {
    case WM_CLOSE:
      DestroyWindow(hwnd);
    break;
    case WM_DESTROY:
      PostQuitMessage(0);
    break;
    default:
      return DefWindowProc(hwnd, msg, wParam, lParam);
  }
  return 0;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
  LPSTR lpCmdLine, int nCmdShow)
{
  WNDCLASSEX wc;
  HWND hwnd;
  MSG Msg;

  //Step 1: Registering the Window Class
  wc.cbSize    = sizeof(WNDCLASSEX);
  wc.style     = 0;
  wc.lpfnWndProc  = WndProc;
  wc.cbClsExtra  = 0;
  wc.cbWndExtra  = 0;
  wc.hInstance   = hInstance;
  wc.hIcon     = LoadIcon(NULL, IDI_APPLICATION);
  wc.hCursor    = LoadCursor(NULL, IDC_ARROW);
  wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
  wc.lpszMenuName = NULL;
  wc.lpszClassName = g_szClassName;
  wc.hIconSm    = LoadIcon(NULL, IDI_APPLICATION);

  if(!RegisterClassEx(&wc))
  {
    MessageBox(NULL, "Window Registration Failed!", "Error!",
      MB_ICONEXCLAMATION | MB_OK);
    return 0;
  }

  // Step 2: Creating the Window
  hwnd = CreateWindowEx(
    WS_EX_CLIENTEDGE,
    g_szClassName,
    "The title of my window",
    WS_OVERLAPPEDWINDOW,
    CW_USEDEFAULT, CW_USEDEFAULT, 240, 120,
    NULL, NULL, hInstance, NULL);

  if(hwnd == NULL)
  {
    MessageBox(NULL, "Window Creation Failed!", "Error!",
      MB_ICONEXCLAMATION | MB_OK);
    return 0;
  }

  ShowWindow(hwnd, nCmdShow);
  UpdateWindow(hwnd);

  // Step 3: The Message Loop
  while(GetMessage(&Msg, NULL, 0, 0) > 0)
  {
    TranslateMessage(&Msg);
    DispatchMessage(&Msg);
  }
  return Msg.wParam;
}