windows-7 - Python pip not working for scipy, scikit-learn and gensim

Question

I'm trying to install scipy, scikit-learn, and gensim on Windows 7 with Python 3.3. If I try any of these: pip install sci

pip install scipy
pip install scikit-learn
pip install gensim

I end up with an ImportError similar to:

ImportError: no module named numpy

And yes, I have installed numpy - it works fine if I try to import it in Python. I've managed to install scipy and scikit-learn by downloading executable installers, but gensim doesn't have one... I've also tried using easy_install for all three, but that doesn't work either.

Is it something to do with the Python installation? Any ideas? Thanks a lot in advance!