C / C++ / MFC

// include this header only once - and create and 
// include a def file in your project - e.g.
 
/*
; TestHook2 : Declares the module parameters.
 
SECTIONS .Whatever READ WRITE SHARED
*/
 
LRESULT CALLBACK HookDeMostrarFinestres(int nCode, WPARAM wParam, LPARAM lParam);
 
// you must define a segment as SHARED in  the .def file...
#pragma data_seg (".Whatever")        
// one instance for all processes
HHOOK   g_hHookMostrarFinestres = NULL; 
#pragma data_seg ()
 
 
class CCaptain {
private:
public:
    // public member declarations
    CCaptain();
    virtual ~CCaptain();
};
 
CCaptain::CCaptain(){
   g_hHookMostrarFinestres =
   SetWindowsHookEx(WH_KEYBOARD,(HOOKPROC)HookDeMostrarFinestres,NULL,NULL);
}
 
CCaptain::~CCaptain(){
    UnhookWindowsHookEx(g_hHookMostrarFinestres);
}
 
LRESULT CALLBACK HookDeMostrarFinestres(int nCode, WPARAM wParam, LPARAM lParam)
{ 
    MessageBeep(-1);
    if (nCode == HC_ACTION) { MessageBeep(-1); }  // will beep twice...
    return CallNextHookEx(g_hHookMostrarFinestres, nCode, wParam, lParam);
}
 
// declare the hook - so all you do is include this file (once)
static  CCaptain Hook;