Simplest windows win32 GUI program ?

win32hello.c

#include <windows.h>
int WINAPI winmain(HINSTANCE hinstance,
                   HINSTANCE hPrevInstance,
                   LPSTR lpszargument,
                   int nWindowStyle)
{
 MessageBox(HWND DESKTOP,
            "Hello World",
            "This is a simple Windows Program",
             MB-OK);
		return 0;
}