Fixed #19344: note for users of Windows + virtualenv

docs/intro/tutorial01.txt

@@ -72,6 +72,17 @@ work, see :doc:`Troubleshooting </faq/troubleshooting>`.
    </ref/django-admin>` is installed, then run the command
    ``sudo chmod +x django-admin.py``.
 
+.. admonition:: Running virtualenv on Windows
+
+   If you used virtualenv_ to :ref:`install Django <installing-official-release>`
+   on Windows, you may get an ImportError when you try to run
+   ``django-admin.py startproject``. This is because Windows does not run the
+   Python interpreter from your virtual environment unless you invoke it
+   directly. Instead, prefix all commands that use .py files with ``python``,
+   like so: ``python django-admin.py startproject mysite``.
+
+.. _virtualenv: http://www.virtualenv.org/
+
 .. note::
 
     You'll need to avoid naming projects after built-in Python or Django