title: Can't install Pillow in Windows
body: <p>The installation process asks for zlib and I even setup &amp; cloned it from Github. I'm new to all of this.</p>
  
  <p>Error message:</p>
  
  <pre><code>C:\Users\GThell\Pillow&gt;pip install -e .
  Obtaining file:///C:/Users/GThell/Pillow
  Requirement already satisfied: olefile in c:\users\gthell\appdata\local\programs\python\python36\lib\site-packages (from Pillow==3.5.0.dev0)
  Installing collected packages: Pillow
    Running setup.py develop for Pillow
      Complete output from command c:\users\gthell\appdata\local\programs\python\python36\python.exe -c "import setuptools, tokenize;__file__='C:\\Users\\GThell\\Pillow\\setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" develop --no-deps:
      Single threaded build for windows
      running develop
      running egg_info
      writing Pillow.egg-info\PKG-INFO
      writing dependency_links to Pillow.egg-info\dependency_links.txt
      writing requirements to Pillow.egg-info\requires.txt
      writing top-level names to Pillow.egg-info\top_level.txt
      warning: manifest_maker: standard file '-c' not found
  
      reading manifest file 'Pillow.egg-info\SOURCES.txt'
      reading manifest template 'MANIFEST.in'
      warning: no previously-included files found matching '.coveragerc'
      warning: no previously-included files found matching '.editorconfig'
      warning: no previously-included files found matching '.landscape.yaml'
      warning: no previously-included files found matching 'appveyor.yml'
      warning: no previously-included files found matching 'tox.ini'
      warning: no previously-included files matching '*.pyc' found anywhere in distribution
      warning: no previously-included files matching '*.so' found anywhere in distribution
      writing manifest file 'Pillow.egg-info\SOURCES.txt'
      running build_ext
  
  
      The headers or library files could not be found for zlib,
      a required dependency when compiling Pillow from source.
  
      Please see the install instructions at:
         http://pillow.readthedocs.io/en/latest/installation.html
  
      Traceback (most recent call last):
        File "C:\Users\GThell\Pillow\setup.py", line 778, in &lt;module&gt;
          zip_safe=not debug_build(), )
        File "c:\users\gthell\appdata\local\programs\python\python36\lib\distutils\core.py", line 148, in setup
          dist.run_commands()
        File "c:\users\gthell\appdata\local\programs\python\python36\lib\distutils\dist.py", line 955, in run_commands
          self.run_command(cmd)
        File "c:\users\gthell\appdata\local\programs\python\python36\lib\distutils\dist.py", line 974, in run_command
          cmd_obj.run()
        File "c:\users\gthell\appdata\local\programs\python\python36\lib\site-packages\setuptools\command\develop.py", line 34, in run
          self.install_for_development()
        File "c:\users\gthell\appdata\local\programs\python\python36\lib\site-packages\setuptools\command\develop.py", line 119, in install_for_development
          self.run_command('build_ext')
        File "c:\users\gthell\appdata\local\programs\python\python36\lib\distutils\cmd.py", line 313, in run_command
          self.distribution.run_command(command)
        File "c:\users\gthell\appdata\local\programs\python\python36\lib\distutils\dist.py", line 974, in run_command
          cmd_obj.run()
        File "c:\users\gthell\appdata\local\programs\python\python36\lib\distutils\command\build_ext.py", line 339, in run
          self.build_extensions()
        File "C:\Users\GThell\Pillow\setup.py", line 549, in build_extensions
          raise RequiredDependencyException(f)
      __main__.RequiredDependencyException: zlib
  
      During handling of the above exception, another exception occurred:
  
      Traceback (most recent call last):
        File "&lt;string&gt;", line 1, in &lt;module&gt;
        File "C:\Users\GThell\Pillow\setup.py", line 790, in &lt;module&gt;
          raise RequiredDependencyException(msg)
      __main__.RequiredDependencyException:
  
      The headers or library files could not be found for zlib,
      a required dependency when compiling Pillow from source.
  
      Please see the install instructions at:
         http://pillow.readthedocs.io/en/latest/installation.html
  </code></pre>