public static void Unregister() { if (!registered) { return; } // In this sample the extension owns the file extension and ProdId, which makes it save to remove // it during unregistration. This is often not the case for file extension for application by other vendors. // In those cases the file extension and ProdID should not be removed. RootKey.Unregister(FileExtension, ProgId); registered = false; //// SHChangeNotify(SHCNE_ASSOCCHANGED, SHCNF_IDLIST, NULL, NULL); }