If you have been hitting this error:

error: Setup script exited with error: Python was built with Visual Studio 2003;

extensions must be built with a compiler than can generate compatible binaries.
Visual Studio 2003 was not found on this system. If you have Cygwin installed,
you can try compiling with MingW32, by passing “-c mingw32″ to setup.py.

trying to install pycrypto on windows, http://blog.sadphaeton.com/2009/01/20/python-development-windows-part-2-installing-easyinstallcould-be-easier.html#comment-8 gives a great article on how to tell easy_install to use the mingw32 compiler instead of Visual Studio.

As of this writing, there was an error on the article which says you need to put a disutils.cfg file in ..python/lib/distutils/. The file name should be distutils.cfg.