I've installed in my machine in the following order python 2.5 numpy 1.01 matplot lib 0.87 scipy 0.52 wxPython 2.8 with no problem I've also installed the same packages at home and in another two computer and everything went fine. The I was asked to install this "configuaration" in some classroom machines and also on another computer and I continue getting this error The import of the numpy version of the _transforms module, _ns_transforms, failed. This is is either because numpy was unavailable when matplotlib was compiled, because a dependency of _ns_transforms could not be satisfied, or because the build flag for this module was turned off in setup.py. If it appears that _ns_transforms was not built, make sure you have a working copy of numpy and then re-install matplotlib. Otherwise, the following traceback gives more details: Traceback (most recent call last): File "", line 1, in <module> from pylab import * File "C:\Python25\Lib\site-packages\pylab.py", line 1, in <module> from matplotlib.pylab import * File "C:\Python25\Lib\site-packages\matplotlib\pylab.py", line 201, in <module> from axes import Axes, PolarAxes File "C:\Python25\Lib\site-packages\matplotlib\axes.py", line 14, in <module> from artist import Artist, setp File "C:\Python25\Lib\site-packages\matplotlib\artist.py", line 4, in <module> from transforms import identity_transform File "C:\Python25\Lib\site-packages\matplotlib\transforms.py", line 223, in <module> from _transforms import Value, Point, Interval, Bbox, Affine File "C:\Python25\Lib\site-packages\matplotlib\_transforms.py", line 17, in <module> from matplotlib._ns_transforms import * ImportError: DLL load failed: Impossibile trovare il modulo specificato but I can assure that If I check numpy installation before installing matplot lib it seems everything fine. All computer have Windows XP home edition 2002 SP2 the only difference is in the RAM quantity. (more than 256 in the computer where everything works) but it seems so strange to me that it is the ram (I've also installed in another computer , old one, and everything works) Any IDEA ???? Thanks in advance for any suggestion Giorgio