The original system is the computer the hard disk came from. you mentioned you have tried it in an external cage; I thought you might not have the original system.
Ubuntu is a good Linux distro found at http://www.ubuntu.com/
if you download the live CD version from here
you can then copy it to a CD. It has been my experience that Linux is able to perform wonders in the data recovery area with very little effort.
Simply download the file and use a CD authoring suite to extract the contents to the CD. Put the CD in and start the system. If it works then you will be able to navigate to your files and folders by going to (in Ubuntu) Places=>My Computer=> File system
Then you can copy the files to a USB drive.