If you're a fan of character-based interfaces -- such as DOS -- and free data recovery, you're going to love TestDisk and its companion utility, PhotoRec (a brother program included in the TestDisk download). Both free programs run in a DOS box or from a command line and test, report on, fix common disk boot problems, and recover files from damaged hard drives. All this is done at low level, below the operating system.
You don't install TestDisk and PhotoRec. You simply unzip the archive to the location from which you want to run it. This may be a bit confusing for users used to installing, but it makes the apps portable, which is far more important to the techier types who are the intended audience. Simply drag the files around on your flash drive and run them from there. Being portable also makes these utilities suitable for inclusion on boot discs. Though character-based, TestDisk and PhotoRec are just as easy to use as a GUI-based program. The options are logically laid out, the language readily understandable for anyone comfortable with command-line utilities, and you simply cursor up and down, right and left to navigate. The way the cursor control is facilitated to accommodate two functions per page is actually quite clever.
I ran both programs through their paces and they worked quite well. They accurately reported the types of drives I had attached to my system and recovered all the deleted files I threw at them -- regardless of an existing partition or not. There were some misfires in the recognition, but there are in every recovery program I've ever used. But I'm definitely going to give both TestDisk and PhotoRec a long hard look in future repair operations. I like character-based utilities.