Python 3.4 install on Windows for multiple users:

Run the installer and choose the following options:

Install for All

Install into

C:\progra~1\Python34

This places the Python34 directory into C:\Program Files.  This is necessary so that ordinary users cannot write into the Python34 directory.  If the Python34 directory is placed at the default location, C:\Python34, then ordinary users can write and delete files in the directory.

The tilde is important! If you use C:\Program Files\Python34 the space in the file name breaks pip and other tools!

Open CMD as Administrator

pip3.4 install virtualenv

This installs virtualenv into C:\progra~1\Python34\Scripts and makes virtualenv available for all users.

DONE

=====

Each user should then be able to

Open CMD:

virtualenv venv

venv\Scripts\activate

pip3.4 install ipython[all]