If you can see this screen, it should mean that Python is already installed. Please cancel this part (or close the window).
I’m not sure what you expect to be able to do at this point. If you think that you should be able to run from the icon on your desktop, that is not how Python works - because it is a tool that you use to make your own programs (or run someone else’s), not just a program that you run directly. The installer won’t normally give you a desktop shortcut, because there isn’t really anything for it to shortcut to. So you’re getting this because you try to use the installer again.
Please try to open a CMD window, and run the command py.
Correct. The screen you show says “Modify setup” so that means you already have Python installed. Now whether your paths are set up correctly is another matter. Set up your paths correctly when you open a DOS box.
Here’s my addpath.bat file I use which is in c:\(myname)\addpath.bat.
@echo off
set path=c:\windows;c:\windows\system;c:\windows\system32;c:\users\(yourusername)\AppData\Local\Programs\Python\Python311;c:\users\(yourusername)\AppData\Local\Programs\Python\Python311\scripts;c:\users\(yourusername)\AppData\Local\Programs\Python\Python311\lib;C:\Users\(yourusername)\AppData\Local\Programs\Python\Python311\Lib\idlelib;c:\users\(yourusername)\AppData\Local\Programs\Python\Python311\lib\site-packages\PyQt6\Qt6\bin
set PYTHONPATH=c:\users\(yourusername)\AppData\Local\Programs\Python\Python311\scripts
set PYTHONHOME=c:\users\(yourusername)\AppData\Local\Programs\Python\Python311
And in a shortcut to a cmd.exe box, the Target field would be: C:\Windows\System32\cmd.exe /k c:\(youruser)\addpath.bat
Set your Start In directory for the cmd.exe box to whatever you want, like the root dir of all your python programs, which might be c:\(youruser)\PythonPrograms\.