Test Tool, have you been able to get it to install?

There are potentially TWO places if you're installing Python on Windows where you may need to do something with the path.

The first page of the python installer will ask you if you want to allow it to update the PATH environment variable.  You need to SELECT this box before you click next to install.  Also at the end of the installer it may ask you to permit Python to override the initial PATH limit of 260 characters.  On a Window system that's been running for a while you will find you will need to do this - for example, with One Drive, Dropbox. Python and the general bloat of the OS my PATH variable is 637 characters!

After enabling both of these, everything works with the instructions provided earlier.

Worked out for me.  I did choose the option at the end of the installer to permit Python to override the initial Path limit just to be safe.

I was able to install the test tool using python 3.9. 

The testtool runs, but shows "not responding" sometimes, and the Output field stays blank, sometimes.