RegShot and WhatChanged are both free, but only RegShot is open source. RegShot takes snapshots of the registry and compares them, telling you the registry values and keys that have been added, removed, and modified going from the first snapshot to the second. You can save snapshots of the registry with it to *.hiv files. You can run RegShot in one prefix, get the *.hiv, save it, run RegShot in the other prefix, save the snapshot *.hiv file, and have RegShot compare the two. That will show any registry differences. Maybe you can make a script that shows the differences between two directories: http://www.astahost.com/info.php/Bash-Shell-Scripting-Comparing-Directories_t19548.html Cheers, Jake
