I use the Anaconda Python distribution: Python 2.7 x64 with Windows 7 SP1 x64 Ultimate.
When I do import matplotlib.pyplot I get ImportError: DLL load
import matplotlib.pyplot
ImportError: DLL load
Try downgrading to a lower version, this command worked for me:
conda install libpng=1.6.22
This downgrades matplotlib and some other packages too, but seems to play well together.