It's rather dangerous procedure to repair drive partitions on a corrupted hard drive. There are lots of possibilities to lose your data, even if you utilize the greatest tool set and absolutely sure in all your actions. Changes made to the corrupted disk are irrevocable; it is really easy to destroy an important system structure that holds essential info about your disk, files and data. First of all the backup should be created before the beginning of data recovery process.
There's a different approach to do data repairing even more harmless, and without having to backup and restore files shall something go incorrect. You cannot make a backup copy of the drive, but you can create a complete binary image of it or its partition. Then you can persist recovering with different approaches for so many times as you wish. This is one of the possibilities of data recovery software.