In Windows 10, click on Windows Button > Gear symbol ⚙ (Settings) > System > About (in the right corner), then select Advanced select settings. A window will pop up, select Environmental variables
If you've installed Python with PATH .bin, you should delete the Python path. To do so, delete these:
C:\Users\[YOUR_USERNAME]\AppData\Local\Programs\Python\Python39\Scripts\ C:\Users\[YOUR_USERNAME]\AppData\Local\Programs\Python\Python39\
Also, in System variables, if you find Python value, delete it as well.
After doing above step, go to: C:\Users\YOUR_USERNAME]\AppData\Local\Programs and delete Python folder. This folder contains all Python versions installations.
After, these above steps, go to Control Panel > choose Uninstall a program . Find Python with version number you've installed, right-click on it, choose Change > Repair, wait till it reinstalls required files.
Then go and again right-click on Python Program > Change > Uninstall