how do you try to run it?
can you locate the file main.py in path_to_your_python\share\kivy-examples\demo\showcase\main.py?
make sure you are trying to run it withe the correct python version where you installed kivy
can you locate the file main.py in path_to_your_python\share\kivy-examples\demo\showcase\main.py?
make sure you are trying to run it withe the correct python version where you installed kivy