Dear #LazyWeb:

I need to find a zero-price program for #Win10 that can act as a little "public address" system. Basically, they've got a room, a cheap computer, a microphone, and speakers; they have no budget (nor do I), and they expect me to do some magic.

Further: I won't be on-site when they do this, so I have to show a non-techie how to use it.