No Module of this name found

[snippsat]

By the way, I thought PIP was a linux package manager. I didn't know that it could be used with Windows.

pip is Python installer for all OS.
You should upgrade,this is easier and better the troubleshoot that error on 3.5.
Python 3.6/3.7 and pip installation under Windows.
Test install pillow,Python 3.7 and pip 18.1.

C:\>pip -V
pip 18.1 from c:\python37\lib\site-packages\pip (python 3.7)

C:\>pip install pillow
Collecting pillow
  Downloading https://files.pythonhosted.org/packages/aa/49/e9de895c7baab95f9b3ab6c8df272edcabba3c92046b008cfa4650fe6eea/Pillow-5.3.0-cp37-cp37m-win32.whl (1.4MB)
    100% |████████████████████████████████| 1.4MB 2.3MB/s
Installing collected packages: pillow
Successfully installed pillow-5.3.0

C:\>