No module named serial
Solution 1:
Serial is not included with Python. It is a package that you'll need to install separately.
Since you have pip installed you can install serial from the command line with:
pip install pyserial
Or, you can use a Windows installer from here. It looks like you're using Python 3 so click the installer for Python 3.
Then you should be able to import serial as you tried before.
Solution 2:
You must pip install pyserial first.