I've been playing around with concrete now for a little while and thought I'd post up a solution to the troubles I was having with the compare versions feature, I didn't know exactly where to put it and thought here was as good a place as any.

Since I'm running windows, chmod doesn't work in the same way that it works on Unix + Linux, so I went looking for another solution to the problem.

What I found was py2exe, a program that converted the python script to an executable for the php to use instead.

I used some friendly help from this website to create my solution.http://logix4u.net/Python/Tutorials/How_to_create_Windows_executabl...

What I did was firstly download and install python 2.6, and py2exe, and installed both of these programs.

Then I added the python install directory into my windows system path, as it hadn't done so automatically.

Next I went to the directory I had installed concrete5 to and went into the concrete\libraries\3rdparty directory. In this directory I created a new folder called htmldiff.

this is where I copied my htmldiff.py file into.

Next in this same directory I created a python script called setup.py and edited it using notepad, and put the following text into it.

## - copy from here
from distutils.core import setup
import py2exe
setup(console=['htmldiff.py'])
## - upto here

then I opened up a command window and navigated to the newly created htmldiff directory. eg.
cd d:\www\concrete\libraries\3rdparty\htmldiff

and ran the following command. "python setup.py py2exe" without the quote marks.

this should then convert the .py file to an exe file located in the htmldiff/dist directory.

and the last step was to change the file concrete/config/base.php
to read '/htmldiff/dist/htmldiff.exe' instead of '/htmldiff.py'.

from here its your choice whether you want to uninstall python or py2exe or keep them.

Hope this is of some help to you.