Thanks Knute
However the problem for windows (as usual) is more difficult. In addition
to the PATH I needed the following to set up the association.
First get check the associated name of the python file type.
In an admin command prompt run the following
* assoc {Python} result "no association.."
*
* I created one
Python="C:\Program Files (x86)\LilyPond\usr\bin\python.exe" "%1"
Now I look in Default Apps and there is PYTHON
SUCCESS!
Now convert-ly.py works
I could have use something Lily specific as the association PYTHONLILY say
maybe I will later.
I expect I will have to do something similar if I go back to PYTHON proper.
Isn't Windows wonderful ????
Regards Peter