I am trying to install Kwant on my Windows-8 system. (I am new to this. I have never used Python.) I tried to follow the instructions on the web page http://kwant-project.org/install#microsoft-windows. The final step in the installation is the following command:

python3 -c "import pip, glob; pip.main(['install', '--no-deps'] + glob.glob('*.whl'))"

When I try to execute this, I get a message that says ‘python3’ is not recognizable as a command. Can anyone tell me what I've done wrong?

Thanks.