In computing, data recovery is a process of salvaging inaccessible data from corrupted or damaged secondary storage, removable media or files, when the data they store cannot be accessed in a normal way. The data is most often salvaged from storage media such as internal or external hard disk drives (HDDs), solid-state drives (SSDs), USB flash drives, magnetic tapes, CDs, DVDs, RAID subsystems, and other electronic devices.

The most common data recovery scenario involves an operating system failure, malfunction of a storage device, accidental damage or deletion, etc. (typically, on a single-drive, single-partition, single-OS system), in which case the goal is simply to copy all wanted files to another drive. This can be easily accomplished using a Live CD, many of which provide a means to mount the system drive and backup drives or removable media, and to move the files from the system drive to the backup media with a file manager or optical disc authoring software. Such cases can often be mitigated by disk partitioning and consistently storing valuable data files (or copies of them) on a different partition from the replaceable OS system files.

Another scenario involves a drive-level failure, such as a compromised file system or drive partition, or a hard disk drive failure. In any of these cases, the data cannot be easily read. Depending on the situation, solutions involve repairing the file system, partition table or master boot record, or drive recovery techniques ranging from software-based recovery of corrupted data, hardware- and software-based recovery of damaged service areas (also known as the hard disk drive's "firmware"), to hardware replacement on a physically damaged drive. If a drive recovery is necessary, the drive itself has typically failed permanently, and the focus is rather on a one-time recovery, salvaging whatever data can be read.

In a third scenario, files have been "deleted" from a storage medium. Typically, the contents of deleted files are not removed immediately from the drive; instead, references to them in the directory structure are removed, and the space they occupy is made available for later overwriting. For the end users, deleted files are not discoverable through a standard file manager, but that data still technically exists on the drive. In the meantime, the original file contents remain, often in a number of disconnected fragments, and may be recoverable.

The term "data recovery" is also used in the context of forensic applications or espionage, where data which have been encrypted or hidden, rather than damaged, are recovered.

Managing and protecting your critical data (avoiding ever needing data recovery services) and having a good disaster recovery plan are essential components to keeping your business healthy:

• 60% of companies that lose all their data will shut down within 6 months of the disaster
• 1 in 5 computers suffers a fatal hard drive crash during their lifetime
• 2,000 laptops are stolen or lost every day
• 60% of a company's mission-critical data resides on hard drives that are not being backed up

Best way to prevent data loss is to have backups.