CHM file for Python 2.5 documentation does not work when being used
without Python installation.

My OS is: Microsoft Windows XP (sp2)

Steps on how to reproduce:

prerequisite:
1) No python has been installed on machine (not sure if necessary)

steps:
1) Download Python25.chm from
http://www.python.org/download/releases/2.5.2/ (md5 digest:
4c2f7e124287525a93849b0b53893bf0)
2) Open file Python25.chm by double clicking on it using file explorer.

noticed behaviour ==> 

Help window opens with navigation pane (on the left) showing index but
on the right window pane there is only a text saying that navigation to
website has been cancelled. When clicking on any item in the navigation
pane still no other text gets displayed on the right window pane else
than "Navigation to website has been cancelled".

expected behaviour ==>

Help window shows documentation in the right hand side window pane.

Oh I found out myself: the file is ok. When the message gets displayed
it has to do with security settings in Windows XP:

Solution:

Right click on the file in file explorer and choose properties in order
to open the properties dialog.
Click on "allow" under security.