Recover Hard Drive Data - Methods of Recovery

Data retrieval refers to the act of obtaining digitalA simple hardware repair will involve replacing a
data from sources, from which the data may not bedamaged printed circuit board with a new working
easily available or accessible. There may be variousprinted circuit board, replacement of read/write head
reasons due to which the digital data may haveassembly, taking out operational hard disk platters
become inaccessible or may not be directly available.from the damaged hard disk and installing them on a
The most common reasons include the data gettingworking hard drive for reading. Most of these
corrupt, the data storage medium may get damagedprocedures are highly technical and are not at all
or dysfunctional, the data or the data source maysuggested to be tried by the en- user at home. This
have been accidentally or intentionally destroyed. Themay result in nullification of the manufacturer's
data needs to be retrieved for using it again,warranty on the product.
extracting hidden information, forensic reasons, etc.Disk imaging
There are many common and scientific methods andThis is a highly scientific, sophisticated and specialized
systems to recover hard drive data available, whichmethod of data retrieval. In this method, each and
include:every readable bit of the damaged hard disk is read
Physical Damage:from its disk surfaces. These read bits are
Physical damage may be caused to different datatransferred to a working hard disk to create a
storage devices in different ways such as:complete image of the damaged hard disk. This
- CD-ROMs can become unreadable due to theextracted raw image is then utilized to recreate the
scratching of the metallic substrate or dry layersdata sets or data structure to identifiable any
- Hard disks can crash by falling down, heads gettingpossible reusable data.
broken, motors getting failedLogical Damage
- Tapes can directly breakIn case of logical damages there are two types of
In most of the cases of physical damage, the repairtechniques that are generally used:
or data retrieval can not be done by common users.Consistency checking
For example, as common users cannot just open theIn this first method called consistency checking, the
hard disk because of its very sophisticatedlogical structure of the hard disk is scanned to ensure
construction. If the hard disks are opened in normalthat the structure is intact and consistent. At least,
environments, it can lead to further damage as suchthere should be two pointers in each directory, one
environment is not safe for minute electronic circuitry.referring to itself and second to its parent directory.
Even minor dust particles in the air can damage theSimple file structure repair software will check and
read heads and disks of the hard disks.create those pointers for each directory where ever
Recover hard drive data process may actually causerequired.
more damage to the hard disk. Also specializedData carving
hardware and expertise is required for such tasks,The second data retrieval technique is called data
which is generally lacking in the common user.carving. This technique is used when the file system
Therefore, there are specialized data retrieval andor file structure is missing in the hard disk. In such a
recovery companies which perform these tasks.case, sectors and clusters are defined in the disk.
However, proper and qualified data retrieval firmsThe unmarked sections of disk are scanned to
need to satisfy some minimum norms or standards.identify any possible file association data to
These firms have to use a minimum "Class 100" /reconstruct the information.
ISO-5 clean room facilities to protect the media whileThough all of these systems are highly technical and
repairs are being made.may not be performed by you, the common user,
The methods of data retrieval used by these firmsbasic knowledge of these techniques can help you
are:easily assess which method will be appropriate to
Hardware repairrecover hard drive data if your hard disk crashes.