If you use XP still (I do) and find that Chord Builder has suddenly gone silent, its possibly the fault of WMP if you tried to use it for playing midi files. It can reset your Soundcard "Midi" fader to Zero.
So if this happens go to Control Panel - Sounds and Audio devices - Audio - sound playback - volume - and then reset your fader to where you want it.
HTH
Ian

Hi Ian.

I finally wrenched myself away from XP and I'm now in the wonderful world of 8.1 - strangely without problems!

I do, however, know lots of folk still happily on XP (and why not?) so that info will be really useful.

Cheers, ROG.