How do I recover the files from formatted hard drives?

TestDisk is powerful free data recovery software! It was primarily designed to help recover lost partitions and/or make non-booting disks bootable again when these symptoms are caused by faulty software, certain types of viruses or human error (such as accidentally deleting a Partition Table). Partition table recovery using TestDisk is really easy.

just run simply in terminal, type
# photorec

and follow instruction in terminal.
the recovery tool will see like screen-shot bellow

PhotoRec in action:


download your copy here