I am referring to these: http://codespeak.net/py/dist/install.html
When installing py.test, the main python installation adirectory and Scripts subdir (e.g. "C:\Python2.6\" and "C:\Python2.6\Scripts") must be added to the windows path.
This issue is only mentioned in the "troubleshooting" section, which points here: "http://docs.python.org/faq/windows#how-do-i-run-a-python-program-under-windows". However, this link does not mention the need to add the <python>\Scripts directory, so it really does not help the user at all.
On a side note, I think the installation guide is too complicated. Anything that requires more than zero thought and 30 seconds is deterring users who are "shopping" for testing frameworks.