@ which tutorial?
Testdisk Step by Step:
http://www.cgsecurity.org/wiki/TestDisk_Step_By_StepRead all the steps, you need to understand what you do.
About Zar... I don't like it.
I.e.: here the list of supported format files:
http://www.z-a-recovery.com/man-valformats.htmNot so many...
Most of my files are .avi. or .mkv!!!
In Linux I have many tarball (tar.gz, tar.bz2, etc), deb & rpm, different format audio (like .ogg), some script (.sh or without extension). So.... it would not be useful to a user like me.
What types of files you have on that hard drive, mainly?
Photos? Music? What...