I feel most people have pip installed already with Python. On Windows, one way to check for pip is to open Command Prompt and typing in:
python -m pip
If you get Usage and Commands instructions then you have it installed.
If python was not found though, then it needs to be added to the path. Alternatively you can run the same command from within the installation directory of python.
If all is good, then this command will install BeautifulSoup easily:
python -m pip install BeautifulSoup4
Screenshot:
N' now I see I need to upgrade my pip, which I just did :)