I installed the PIL library using the .exe installer of the version 4.0.0 taken from this site (The Python Software Foundation website). Then I checked using the python shell if the PIL library was installed and it didn't give me error, so I assumed that's installed. Then I tried to copy from the installation folder of the library the folder named PIL into the folder C:\Program Files\Blender Foundation\Blender\2.78\python\lib. Then I tried to put in a text "import PIL", and it worked. (Before doing the copy of the folder PIL told me that no PIL modules were installed). Then I tried: "from PIL import Image" and it gave me errors. Any way to make blender use properly the PIL library?
EDIT: The error it gave me it's the following:
Traceback (most recent call last): File "\Text", line 1, in <module> File "C:\Program Files\BlenderFoundation\Blender\2.78\python\lib\PIL\Image.py", line 67, in <module> from PIL import _imaging as core ImportError: cannot import name '_imaging'