Data recovery is the method of recovering unavailable, missing, deleted, destroyed, or formatted data from secondary storage, portable media, or files when the data stored there can’t be accessed normally. Physical or logical damage to the file system that prevents the host operating system from mounting it can cause recovery (OS).

The most common data recovery scenario includes an operating system failure, storage device malfunction, storage device logical failure, unintended damage or deletion, and so on (typically on a single-disk, single-partition, single-OS system), in which case the ultimate aim is to copy all essential files from the damaged media to another new drive. This can be conveniently done by booting directly from a ROM instead of the corrupted drive using a Live CD or DVD. Many Live CDs or DVDs have the ability to mount the system drive and backup drives or removable media, as well as use a file manager or optical disc authoring programme to transfer files from the system drive to the backup media.