The thing is: setting VBcable as the default playback device is a quick-and-dirty way to route all
audio through VBcable (and therefore through Stereo Tool, once that is set up correctly).
A drawback of that method is that you might not want some of that audio to go through Stereo Tool.
Another side-effect can be that some programs might not be happy with a virtual output device:
Setting all this settings, Adobe Audition is complaining, that it can't record a live program.
This could be one of the side-effects of setting VBcable as the default, though I'm not sure.
The difficulty, I think is that AerOn works with a Delta soundcard...
The most important thing, is that AerOn (which I am not familiar with) outputs
If there's a setting to do that in AerOn, then there's no need to set VBcable as the default device.
In other words: if you can tell AerOn to output straight to VBcable and ignore the Windows default playback device setting, do that. Then you can put the default playback device in Windows back to whatever it was.
The screenshot regarding SOUND: Speakers should be the Default service, but what should be the Default Communication Device?
I don't really know what the definition of a "Communication Device" is. My guess is that it's used by software like Skype.
But like I said: the most important thing is that AerOn outputs to it.