Disk Warrior is Macintosh software that performs various tasks and recovery on hard drives.
This software can fix or repair drives that are corrupted or damaged. It obviously cannot fix all problems but it can fix many. Recently I used Disk Warrior 4 on a drive that had disconnected during copy. It would not recognize and it appeared that all the data on the drive was lost. After using Disk Warrior the drive was fixed! What a fantastic product. Disk Warrior will not fix all problems but considering how much sentimental and financial value exists in peoples computers these days, it is software that may be worth its weight in gold.