I am fairly new to Python and trying to install the Pillow package on Windows 7. I downloaded and ran the MS Windows installer Pillow-2.2.1.win-amd64-py3.3.exe from here. It
For third-party modules for Windows, my go-to resource is Christoph Gohlke's Python Extension Packages for Windows. You can find the latest version of Pillow here. Make sure you're working with the python.org version of Python.
As far as your specific error, it's hard to tell exactly without a traceback, but make sure your script is calling the correct version of Python. If you have also installed Python 2.7, for example, your script may be calling that instead of 3.3.
In my case , I was referring to wrong pip folder. Changed virtual environment in pycharm to point to right pip folder to solve this issue
import sys
print ( sys.path )
In such cases I'm simply printing the sys.path
at the beginning of the script in trouble and comparing it with the one from the working python interpreter. In most cases I was running the script with a different python interpreter.