#include <windows.h>

int main()
{
  DWORD dwReturnValue;

  LRESULT lrStatus = SendMessageTimeout(
    HWND_BROADCAST,
    WM_SETTINGCHANGE,
    0,
    (LPARAM) "Environment",
    SMTO_ABORTIFHUNG,
    5000,
    &dwReturnValue
  );

  return (lrStatus) ? 0 : 1;
}