I am trying to customize the registry functionality of CWinApp. To do this I am trying to derive another App class from it. I have overriden the GetAppRegistryKey(), GetSectionKey(), and SetRegistryKey() functions so far. I am then trying to use WriteProfileString() to write to a key that is under HKEY_LOCAL_MACHINE. I have not been able to write to anything except the HKEY_CURRENT_USERS hive. Is there a way to do this without resorting to using just the WIN32 API? If so what? Am I missing something obvious? Also would there be any problem putting this class derived from CWinApp into a DLL. If more detail is needed I can supply it.