update installation instructions for windows

content/install.rst

@@ -283,27 +283,29 @@ provided by Christoph Gohlke.  To install Kwant on Windows
 1. Determine whether you have a 32-bit or 64-bit Windows installation by
    following these `instructions <http://support.microsoft.com/kb/827218>`_.
 
-2. Download and install Python 3.4 for the appropriate architecture (32-bit or
-   64-bit) from the official `Python download site
-   <http://www.python.org/download/>`_.
+2. Download and install Python for the appropriate architecture (32-bit: “x86” or
+   64-bit: “x86-64”) from the official `Python download site for Windows
+   <http://www.python.org/download/>`_.  We recommend that you install the
+   latest stable Python 3 release.
 
 3. Open a command prompt, as described in "How do I get a command prompt" at
    the `Microsoft Windows website <http://windows.microsoft.com/en-us/windows/command-prompt-faq>`_.
 
 4. In the command prompt window, execute::
 
-        C:\Python34\python.exe C:\Python34\Tools\Scripts\win_add2path.py
+        C:\Python35\python.exe C:\Python35\Tools\Scripts\win_add2path.py
 
    (Instead of typing this command, you can also just copy it from here and
    paste it into the command prompt window). If you did not use the default
-   location to install Python in step 2, then replace ``C:\Python34`` by the
-   actual location where Python is installed.
+   location to install Python in step 2, then replace ``C:\Python35`` by the
+   actual location where Python is installed.  You may also need to adjust the
+   version (“35” signifies Python 3.5).
 
 5. Reboot your computer.
 
 6. Download the necessary packages (with the ending ``.whl``) for your
-   operating system (32 or 64 bit) and Python version (e.g. ``cp34`` for
-   Python 3.4) from the website of `Christoph Gohlke
+   operating system (32 or 64 bit) and Python version (e.g. ``cp35`` for
+   Python 3.5) from the website of `Christoph Gohlke
    <http://www.lfd.uci.edu/~gohlke/pythonlibs/>`_.  For Kwant, we recommend to
    download at least `NumPy
    <http://www.lfd.uci.edu/~gohlke/pythonlibs/#numpy>`_, `SciPy
@@ -325,9 +327,9 @@ provided by Christoph Gohlke.  To install Kwant on Windows
 
    To install all the ``.whl``-files in the current directory, execute ::
 
-       python3 -c "import pip, glob; pip.main(['install', '--no-deps'] + glob.glob('*.whl'))"
+       python -c "import pip, glob; pip.main(['install', '--no-deps'] + glob.glob('*.whl'))"
 
-   The above cryptic command is equivalent to ``pip3 install --no-deps
+   The above cryptic command is equivalent to ``pip install --no-deps
    *.whl``, i.e. it installs all the wheel files in the current directory
    using pip.  Because the Windows command interpreter does not support globs,
    we have to rely on the globbing as provided by Python itself.