Numerical 17.1.1 is available in both source and prebuilt Windows versions at: http://sourceforge.net/projects/numpy Windows users, simply extract into your top level Python 2.0 directory, typically c:\python20. Thank you to Pete Shinners for putting the Windows file together. It is too late to change for the 17 series but in future I will make releases that have whole numbers only as names and add files to that release as they become available. That makes it a little clearer that you should take the most recent file of the desired type.