HDDRUTIL, HDDRCONF, ZIPCTRL and AUTOPARK support two languages for their user interfaces: English and German. The default language is English, unless the _AKP cookie signals a German TOS. In this case the default language is German.
When the [Alternate] key is being pressed while launching one of these applications, the UI language is toggled between English and German. This means that on a German TOS you can force the language to be English, and on a non-German TOS you can force it to be German.
Furthermore, HDDRUTIL supports permanently setting the UI language in its preferences ("File->Preferences"/"Datei->Einstellungen"). If you do not want HDDRUTIL to derive its language from the TOS (_AKP) setting, just select the language of your choice. Do not forget to save the new preferences, or configure HDDRUTIL to automatically save the preferences on exit. When setting an explicit language you can still toggle the language on startup with the [Alternate] key.
Even HDDRIVER supports English and German, but in this case there is no explicit language selection. The default language is English, unless the _AKP cookie signals a German TOS.