Edit: See my next post! This one is obsolete.
Its very odd that its working on your Windows 8 machine!
There seems to be something wrong with mine. Maybe a problem in the registry?
If you know of a critical registry setting that may be corrupt, perhaps you could let me know, and I'll have a look.
I have another machine running Windows 7. Both Chrome and Firefox(+Jazz) are working perfectly there.
The Chrome Web MIDI implementation is not finding the MS GS Synth either on Windows 8.
Windows Media Player is playing MIDI files on Windows 8, so the MS GS Synth must be there somewhere.
I just checked my plugin settings for both Firefox and Chrome. Discovered something I wasn't expecting:
Jazz was both installed and enabled on Windows 8 Chrome.
I was expecting it not to appear at all (as in the Windows 7 Chrome plugins).
I have now disabled Jazz in Windows 8 Chrome, since I'm using Chrome's Web MIDI flag, but I still have no access to the MS GS Synth, in either Chrome or Firefox(=Jazz), in Windows 8.
1 Coolsoft's VirtualMIDISynth:http://coolsoft.altervista.org/en/virtualmidisynth
Jazz is finding this on both my Windows 7 and Windows 8 machines.
Jazz is findng the MS GS Synth on Windows 7, but not on Windows 8.
I have tried uninstalling the VirtualMIDISynth on Windows 8, to see if there was some kind of conflict, but that does not help. (Jazz then returns an empty output device list.)
I'd be surprised if Coolsoft failed to restore some registry setting when uninstalling the VirtualMIDISynth, but stranger things have happened... The VirtualMIDISynth seems to be very reliable and well programmed.
2. Visual Studio Community Edition 2013:
Visual Studio digs deep into the system, but could a Microsoft product really be the source of the problem?
There are a few other programs installed, but I don't think any of them would tinker with the (MIDI) devices.
Its very odd. The annoying thing is that its not a particularly important problem for me. Maybe it will just go away when Windows 10 arrives. But I'd prefer knowing what's going on anyway!
All the best,