Окно своими руками.

bool CALLBACK MyWinProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
}
WINAPI WinMain(HINSTANCE hInstance, HINSTANCE, LPSTR lpCmdLine, int nCmdShow)
{
  HWND hwndMain;

  WNDCLASS wc;
  wc.style = CS_HREDRAW|CS_VREDRAW;
  wc.lpfnWndProc = (WNDPROC)MyWinProc;
  wc.hInstance = hInstance;
  wc.hbrBackground = (HBRUSH)(COLOR_WINDOW);
  wc.lpszClassName = "MYFIRSTNONVCLAPPLICATION";
  wc.hCursor = LoadCursor(NULL, IDC_ARROW);
  wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
  wc.lpszMenuName = NULL;
  wc.cbClsExtra = 0;
  wc.cbWndExtra = 0;

  if(!RegisterClass(&wc))MessageBox(0, "Class is not registred", "ERROR", MB_ICONERROR | MB_OK), ExitProcess(0);
  else MessageBox(0, "Class is registred", "Seccess", MB_OK);

   hwndMain = CreateWindow(wc.lpszClassName, "Non VCL Programm",
                WS_BORDER|WS_CAPTION|WS_SYSMENU|WS_MINIMIZEBOX,
                CW_USEDEFAULT, 0, 300, 350, NULL, NULL, hInstance, NULL);
  if(GetLastError() == 1400)MessageBox(0, "Window is not created", "ERROR", 0);
  ShowWindow(hwndMain, SW_SHOWNORMAL);

        return 0;
}