virtualenv wrecked my Django+modules install

[Alec Taylor]

Good morning,

On my system (Windows 8 Developer Preview x64 with Python 2.7.2 x64) I
painstakingly installed all the dependencies for Django, Satchmo and a
few other large scale projects.

(about 10% couldn't be installed with pip, which is why I use the word
'painstakingly')

Recently though I needed Pinax for something, so following there guide
(http://pinax.readthedocs.org/en/latest/gettingstarted.html) I setup a
virtualenv for it.

Not only could I not get Pinax running, but when I went back to work
on my Satchmo-based project, and ran "manage.py runserver" I got the
following error:
Traceback (most recent call last):
  File "P:\Prototype\Django\store\manage.py", line 18, in <module>
    from django.core.management import execute_manager
ImportError: No module named django.core.management

Typing in `import django` from the interpreter gives me:
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named django

Does this mean I need to install everything required by my project all
over again? - If so, should I take a virtualenv approach (and what
would the advantages be of doing so)?

Thanks for all suggestions,

Alec Taylor