I have therefore compiled an optimized Version for Windows (compatible with Houdini) and attached it to this post.
It's based on Numpy v1.13.3 and OpenBLAS v0.2.20(Multithreaded).
Provided “AS IS”. No warranty, no liability.
Hope it helps some folks on Windows - I did run some Numpy test scripts, but did not test it thoroughly; seems to work quite fast

Please copy the “numpy” folder to your Houdini installation at:
C:\Program Files\Side Effects Software\Houdini <version>\python27\lib
This way you do not have to overwrite/remove your standard numpy package from your Houdini installation, because the
above path is looked at first, before the standard Houdini package.
=> There are no crashes / errors in the numerical parts of the full Numpy testsuite !
However, I had some other errors, which should not be relevant for use in Houdini. Use at your own risk…
(- I also had errors with the full tests with the standard native installation of Numpy 1.13.3 on Windows/Python2.7
(via pip install) and with the un-optimzed Numpy version v1.9.2 running in hython / Houdini on Windows, btw.)
Thanks for any feedback about your tests - Cheers
