The microsoft narrator program voice settings option shows three voices available (anna, mike, mary), but only anna seems to work. When I select one of the others, the text-to-speech is silent.

 

I've also gone to the Text-to-Speech option in the control panel. All three voices are shown there in the drop-down, but when I try to select one other other two selections there, I get a message stating that the voice cannot be played.

 

How can I get make the other voices accessible?