#include <iostream>
#include <windows.h>
 
HHOOK hHRes;
 
LRESULT CALLBACK CBTProc( int , WPARAM , LPARAM );
void ErrorExit(LPTSTR lpszFunction);
 
int main()
{
    char s[500] ={};
    hHRes = ::SetWindowsHookExA( WH_CBT , &CBTProc , GetModuleHandle( NULL ) , 0 );
    if ( hHRes == NULL ) {
       /* le resto 2 para establecer un caracter nulo en formato WCHAR */
       ::FormatMessage( FORMAT_MESSAGE_FROM_SYSTEM , NULL , ::GetLastError() , NULL , (WCHAR*)&s , (DWORD) strlen(&s[0])/2 - 2 , NULL );
       ::MessageBoxExW(NULL,(WCHAR*)&s,NULL,0,NULL);
    }
    return 0;
}
 
LRESULT CALLBACK CBTProc( int nCode, WPARAM wParam, LPARAM lParam )
{
    ::UnhookWindowsHookEx( hHRes );
    return ::CallNextHookEx( hHRes , nCode , wParam , lParam );
}