title: Installing matplotlib using pip gives error
body: <p>I am new to python and is using pip to download and install packages. I ran the following code on my command window and it throws an error</p>
  
  <pre><code>pip install matplotlib
  </code></pre>
  
  <p>And the process starts as </p>
  
  <pre><code>Collecting matplotlib
    Using cached matplotlib-1.5.3-cp27-cp27m-win32.whl
  Collecting numpy&gt;=1.6 (from matplotlib)
    Using cached numpy-1.11.2-cp27-none-win32.whl
  Collecting python-dateutil (from matplotlib)
    Using cached python_dateutil-2.5.3-py2.py3-none-any.whl
  Collecting cycler (from matplotlib)
    Using cached cycler-0.10.0-py2.py3-none-any.whl
  Collecting pyparsing!=2.0.4,!=2.1.2,&gt;=1.5.6 (from matplotlib)
    Using cached pyparsing-2.1.10-py2.py3-none-any.whl
  Collecting pytz (from matplotlib)
    Using cached pytz-2016.7-py2.py3-none-any.whl
  Collecting six&gt;=1.5 (from python-dateutil-&gt;matplotlib)
    Using cached six-1.10.0-py2.py3-none-any.whl
  Installing collected packages: numpy, six, python-dateutil, cycler, pyparsing, pytz, matplotlib
  Exception:
  Traceback (most recent call last):
    File "c:\python27\lib\site-packages\pip\basecommand.py", line 215, in main
      status = self.run(options, args)
    File "c:\python27\lib\site-packages\pip\commands\install.py", line 317, in run
      prefix=options.prefix_path,
    File "c:\python27\lib\site-packages\pip\req\req_set.py", line 742, in install
      **kwargs
    File "c:\python27\lib\site-packages\pip\req\req_install.py", line 831, in install
      self.move_wheel_files(self.source_dir, root=root, prefix=prefix)
    File "c:\python27\lib\site-packages\pip\req\req_install.py", line 1032, in move_wheel_files
      isolated=self.isolated,
    File "c:\python27\lib\site-packages\pip\wheel.py", line 346, in move_wheel_files
      clobber(source, lib_dir, True)
    File "c:\python27\lib\site-packages\pip\wheel.py", line 324, in clobber
      shutil.copyfile(srcfile, destfile)
    File "c:\python27\lib\shutil.py", line 83, in copyfile
      with open(dst, 'wb') as fdst:
  IOError: [Errno 13] Permission denied: 'c:\\python27\\Lib\\site-packages\\numpy\\core\\multiarray.pyd'
  </code></pre>
  
  <p>And it gives these traceback errors. I'm unable to figure out what these errors are and how to solve them. Please help. It works perfectly till collecting the packages but at the time of installing it throws errors.</p>