The location of the prebuilt windows installer for PyCypto 2.0 (for python 2.4) has changed. Apologies for any confusion, this is because of a website reorganisation at Voidspace.
The new location is : http://www.voidspace.org.uk/python/modules.shtml#pycrypto
There is also a prebuilt windows installer for psyco 1.4 (for python 2.4). This is because there isn't yet a prebuilt binary available from sourceforge. http://www.voidspace.org.uk/python/modules.shtml#psyco
Both built using the free, Microsoft, optimizing compiler. Following instructions from : http://www.vrplumber.com/programming/mstoolkit/index.html