I can't seem to install numpy to PyCharm.
I started with an up-to-date, fresh install of Python 2.7.8 and PyCharm 3.4.1.
Then I installed winpython in PyCharm to get the numpy and scipy packages using
File > Default Settings > Project Interpreter > selected Python 2.7.7 > installing pip and setuptools > installing winpython...
After installing these, I went to run a simple code using numpy and continue to get an error of "no module named numpy". My professor did the exact same thing and his works fine (both using Windows 7).
Go to the Winpython website, download the version according to your needs and install it locally. Then open PyCharm and add a new python interpreter giving the path of where you installed Winpython to (the python-... subirectory).
Winpython is a Python distribution, it provides a python environment with packages like Numpy or Scipy precompiled and preinstalled. It's not a package itself (there is one, but this is not the entire distribution!).