Be sure to start
TomTom Home and select the menu
BEFORE the navigation system is connected to the USB, otherwise the menus will be grayed out
And secondly:
How is one supposed to find that "Add voice" is displayed on the first page of TTH and you have to scroll to page 3 to find "Add computer voice" there.
Be sure to note the first point, then you don't have to laboriously and slowly download the files.
Adding the "computer voice" via TTH, inside folder 'voices' I got the missing configuration file, finally. Now, when I click on test on the GO930 it does say its preview sentence