I have Python3.8.7 and my operating system is Windows. I know that Tkinter module is in the standard library so we don't need to install it. But when I try to import it:

I also tried to install it:

(I also looked at the other question in StackOverflow, but it was for Linux and I didn't solve my problem. And also it is too old.)
EDIT: I solved this problem. I executed the installer again and chose the "Modify" option and after that, I chose the "Repair" option. And my problem was solved!

