Data recovery software allows for the process of retrieving or extracting data from a storage device (such as your hard drive) that cannot be retrieved by normal means.
Depending on the type of event that caused the files to disappear – a physical storage problem, a logical storage problem, or both – there are various ways in which one can go about resurrecting files that were thought to be gone forever.
Data recovery software can restore a hard drive crash, where the hard drive itself mechanically no longer works, for example. The other preceding examples, as well as file corruption and damage, are examples of logical storage data losses. Data recovery software can restore lost or damaged files for both types of data loss in many cases.
Generally computer or device physical damage cannot be repaired by users. Opening a hard disk drive in a normal environment will allow dust to settle on the surface of the drive and cause further damage. Most people don't have the technical knowledge required to make these repairs either. Data recovery companies have the knowledge, experience, and sophisticated tools required to perform the recovery. These firms often use Class 100 clean room facilities to protect the media while repairs are being made. Recovering data from physically damaged hardware can involve multiple techniques.
Some damage can be repaired by replacing parts in the hard disk. This alone may make the disk usable, but sometimes a specialised disk imaging procedure is used to recover readable data. Once this image is acquired, the image can be analysed for logical damage and will possibly allow for much of the original files to be reconstructed.