It's really risky procedure to recover drive partitions on a corrupted hard drive. You may even use one of the greatest tool sets and be certain in your deeds, you are still risking to waste your data. Alterations that can be made to the damaged disk are irreversible. You must remember that it is rather simple to overwrite the structure of essential information about your hard dist. First of all the substitute must be created before the start of data recovery procedure.
But there are also some other ways of data repairing that are safer and simpler in usage, that do not need to have substitute and restore info. Instead of making a substitute copy of corrupted files, you can simply create a total binary snapshot of the drive or partition being repaired, and try the fixing with diverse settings as many times as you need on this image instead of the actual drive. This is one of the possibilities of data recovery software.