HKEY_CURRENT_USER\Software\Microsoft\ActiveMovie\devenum\{4EFE2452-168A-11D1-BC76-00C04FB9453B}\Default MidiOut Device
HKEY_CURRENT_USER\Software\Microsoft\ActiveMovie\devenum 64-bit\{4EFE2452-168A-11D1-BC76-00C04FB9453B}\Default MidiOut Device
However I have a piece of software that DOES appear to be able to change the default MIDI output, CoolSoft's VirtualMidiSynth. It appears to successfully change the device from an option in the installation dialog box that sets the default output to the
CoolSoft synth. When I install the program with that option selected, I am able to use programs that can only send to the default output device (there are no options to send to anything else; I wrote some of the code for these programs so I know that for certain)
and they send output to the new synthesizer rather than the MS-supplied synth. When the CoolSoft synth is uninstalled or installed without the device-changing option selected, the MS synth is still used. From this I gather that it must be possible to change
the default MIDI output device. Clearly the two keys above have no impact, since I have tried changing them several times and even rebooted between changes. So, my question is: what other registry keys or other system settings in Windows 8 are responsible
for allowing the default MIDI output device to be changed?
