Even though data recovery software and undelete utilities are both designed to recover deleted and lost files, they are different in two ways: data recovery software offers you multiple functions to handle many different situations, and it can also recover a lot more data.
Cost reflects quality
Data recovery software and undelete recovery utilities can each retrieve lost, deleted, corrupt, and damaged files, and sometimes partition and boot sector problems. Both data recovery and undelete recovery software are designed to retrieve all data loss circumstances, but there is one major difference between the two: Data recovery software is able to rebuild and repair a file system that is not intact to recover data - something undelete data recover software can't do. An intact file system means that the components that hold individual files together have not been changed.
Additional recovery option
In the end, disk data recovery software outperforms an undelete utility
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