Given I have no knowledge of the windows system, I'm just proxying http://mail.python.org/pipermail/docs/2011-September/005793.html :

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Under: http://docs.python.org/install/index.html#inst-how-install-works


It notes "Windows	prefix\Lib\site-packages	C:\PythonXY\Lib\site-packages"
for default values on Windows.

In the paragraph following the table is the text: "prefix and
exec-prefix stand for the directories that Python is installed to, and
where it finds its libraries at run-time. They are always the same
under Windows, and very often the same under Unix and Mac OS X. "

I don't know if it's hardcoded into Python distributions to use C, but
it's not correct. The correct way to identify what most people think
of as C is via the %SYSTEMROOT% environment variable, so the path
described would be "%SYSTEMROOT%\PythonXY\Lib\site-packages"

(This is still not the correct way to do things on Windows, but it at
least shouldn't break on systems with a %SYSTEMROOT% other than C.
I've seen configurations like that on systems which boot multiple
versions of Windows.)
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