It seems there is a way to switch between 3.7 and 2.7 BUT it is complex and opaque. It needs careful downloading of Python 3.7 and some other mysterious messing with "Shebangs" whatever they are and using strange characters such as Greek "lambda" (not on my keyboards). It would seem the game is not worth the candle so 3.7 is in the dustbin and all back to normal.
It is a shame though that 3.7 and Lilypond cannot co-exist easily on Windows 10 at any rate. Regards Peter
