HOW IS DATA RECOVERY PERFORMED?

Data recovery in most cases is a very intricate process.  The first step is to determine if the hard drive failure is being caused
by logical or physical reasons.  One way of determining this is to listen to the hard drive for noises.  Often with a physical problem, there will be a grinding, whining or clicking noise.  This indicates a head crash, which means the read/write heads have landed on the platter.  If this occurs, the hard drive should be powered off and a data recovery company should be contacted immediately.  Operating a drive with this type of problem could mean permanent disaster for the data residing on the platter.  Clicking noises may also originate from bad sectors on the hard disk causing the read/write heads to continually try to access the same area on the platters indicating a servo problem.  Other noises could mean a motor failure, defective spindle, or worn bearings. 

Physical data recovery must be performed by expert technicians in a sterile clean room environment using special recovery equipment and tools.  Opening a hard disk drive outside of this environment can cause dust and debris to settle on the surface of the platters.  If the data on the drive is important, it is crucial to allow a professional data recovery company open
the drive in a clean room.  The chances of a successful recovery depends on the extent of hard drive damage. 

Logical data recovery is often necessary due to damage to the file system.  Such damage can result from various factors including improper shutdown, system crash, power surge and computer viruses.  As a result, the file system is left in an
inconsistent state.  Logical recovery involves repairing file system structures in order to access the data.  It is extremely important not to format the hard drive under any circumstances.  Performing a format will overwrite data that exists on the hard drive and destroy the file allocation table entry.  This will certainly make data recovery more complicated and maybe
impossible.  Most data recovery companies have proprietary tools and techniques to recover data from physical and logical
hard drive failure.