["python","windows"]
How can I check all the installed Python versions on Windows?

Please note I'm not asking "how to check which version of Python did I install". I've installed several versions of Pythons on my Windows computer, for example Python 2.7-64, Python 2.7-32, and Python 3.7-32. Python 3 includes "py" and "pyw" which helps me to easily start different Pythons, for example: "py -2.7" starts Python 2.7-64 "py -2.7-32" starts Python 2.7-32 "py -3.7-32" starts Python 3.7-32 What I'm wondering is, how to check how many different versions of Python did I install on my Windows PC and what versions are they? PyCharm is able to find it but, for one thing, I don't know if it is a complete list, and for another, I wonder if there is any tool provided by Python or the operating system can do it.
I just got the answer. By typing "py -h" or "py --help" I got the help message: C:\Users\admin>py -h Python Launcher for Windows Version 3.7.1150.1013 usage: py [launcher-args] [python-args] script [script-args] Launcher arguments: -2 : Launch the latest Python 2.x version -3 : Launch the latest Python 3.x version -X.Y : Launch the specified Python version The above all default to 64 bit if a matching 64 bit python is present. -X.Y-32: Launch the specified 32bit Python version -X-32 : Launch the latest 32bit Python X version -X.Y-64: Launch the specified 64bit Python version -X-64 : Launch the latest 64bit Python X version -0 --list : List the available pythons -0p --list-paths : List with paths Which tells me that "-0" (zero, not letter "O") lists the available pythons: C:\Users\admin>py -0 Installed Pythons found by py Launcher for Windows -3.7-64 * -3.7-32 -2.7-64 -2.7-32 While "-0p" lists not only the versions, but also the paths: C:\Users\admin>py -0p Installed Pythons found by py Launcher for Windows -3.7-64 C:\Users\admin\AppData\Local\Programs\Python\Python37\python.exe * -3.7-32 C:\Users\admin\AppData\Local\Programs\Python\Python37-32\python.exe -2.7-64 C:\Python27_64\python.exe -2.7-32 C:\Python27_32\python.exe To install a Python version that is not listed there run py install followed by the version number, e.g. py install 3.14