Can't get rid of old version of python

[Terry Reedy]

On 8/13/2021 2:32 PM, Ciarán Ó Duibhín via Python-list wrote:
> Hi,
> 
> On Windows 10, I uninstalled all previous versions of Python and 
> installed v3.9.6.
> 
> When I use the start menu option Python 3.9 (64-bit), I get the prompt 
> "Python 3.9.6" as expected.  The same happens when I type "py" at the 
> DOS prompt.
> 
> But when I type "python" at the DOS prompt, I get "Python 3.8.10".  I 
> don't understand this, as I uninstalled old versions, and I do not see a 
> DOS environment variable called "python" anywhere.
> 
> The real problem comes when I install a package, e.g. germalemma. Python 
> 3.8.10 can use it, but Python 3.9.6 can't find it.

If 'py' starts 3.9, then

py -m pip install xyz

will install xyz for 3.9.  (In not, py -3.9 -m pip ... will)

The command 'python' takes one to the MS store unless one has already 
gotten the store python.

-- 
Terry Jan Reedy