Environment PATH Length Limitation is 1024 characters
Note that the user interface will happily allows you to define a PATH that is way longer than 1024, and will just truncate anything longer than this.
NOTE: Your PATH = SYSTEM_PATH + USER_PATH, so you need to make sure the combined is < 1024.

https://stackoverflow.com/questions/24186823/python-not-recognized-in-windows-cmd-even-after-adding-to-path

