Data recovery is the process of salvaging data from damaged, failed, corrupted, or inaccessible secondary storage media when it cannot be accessed normally. Often the data are being salvaged from storage media such as hard disk drives, storage tapes, CDs, DVDs, RAID, and other electronics. Recovery may be required due to physical damage to the storage device or logical damage to the file system that prevents it from being mounted by the host operating system. The most common "data recovery" issue involves an operating system (OS) failure (typically on a single-disk, single-partition, single-OS system), where the goal is to simply copy all wanted files to another disk. This can be easily accomplished with a Live CD, most of which provide a means to 1) mount the system drive, 2) mount and backup disk or media drives, and 3) move the files from the system to the backup with a file manager or optical disc authoring software. Further, such cases can be mitigated by disk partitioning and consistently moving valuable data files to a different partition from the replaceable OS system files. The second type involves a disk-level failure such as a compromised file system, disk partition, or a hard disk failure —in each of which the data cannot be easily read. Depending on the case, solutions involve repairing the file system, partition table or MBR, or hard disk recovery techniques ranging from software-based recovery of corrupted data to hardware replacement on a physically damaged disk. These last two typically indicate the permanent failure of the disk, thus "recovery" means sufficient repair for a one-time recovery of files. A third type involves the process of retrieving files that have been deleted from a storage media. Although there is some confusion as to the term, the term "data recovery" may be used to refer to such cases in the context of forensic purposes or spying.

Hard drive data recovery is possible on nearly every type of computer system. Our Disk Doctors data recovery lab technicians and engineers are a highly skilled team trained and experienced in the latest state-of-the-art data recovery techniques with years of successful hard drive recovery experience behind them on almost every type of file system and computer system. Generally, hard drives fail or are inaccessible due to one of two common reasons:

Physical Crash: When a hard drive is making ticking or scratching noises due to old or worn out parts it can lose the data contained within. The read / write heads in the hard drive can fail; failed motors are common; or the platters on which the data is stored can become damaged.

Physical damage can also be due to mishandling of the drive or circuit failure of the PCB board which is attached to the hard drive. Physical damage to the disks itself always causes at least some data loss. And, in many cases with physically damaged hard drives, the logic structure of the file system may also get damaged. Any damage of this sort constitutes a physical crash of a hard drive.

Logic Crash: Far more common than physical damage is logical corruption or damage to a file system. Logic damage is primarily caused by human error, which includes accidental deletion of files, accidentally formatting a hard drive, and even power outages can cause file system structures to become damaged. Logical crashes can cause a variety of problems including total system crashes and actual loss of data.