What exactly is data recovery?

Data recovery is a process of reconnecting computer users with their data by extraordinary means.

Data loss occurs when the computer operator is unable to find, locate or connect with their data by ordinary means even though their data may be on the media.
Simple data loss is when a user accidentally deletes a file in this instance with many operating systems such as Microsoft and Apple systems the data can be ‘retrieved’ by reversing the action the file system is informed to keep that file or folder do not mark it as empty space thus the file will not be deleted.
What happens when the user deletes from the trash area or recycle bin or similar?
The computer data now appears to totally lost as the computer system has no means to access this data any more, so a different approach and tools will be required.
The file is now in ‘limbo’ for want of a better description it is neither permanently deleted or accessible to the operating system any further, moreover it is in jeopardy of being overwritten so if the file is of importance then you must immediately shut the computer system down, this will negate the chances of the file being overwritten.
The media must be removed then and installed to a computer system which has a write blocker which will inhibit any writes from taking place to the user data area as the operating system will try and write $meta data at least to the volume which could destroy your data, following the write blocker attachment the hard drive should be examined via a hexadecimal editor which will help the user locate the $MFT master file table with location of file.

If the data has any value to you and you are concerned about losing it then you must consider your actions carefully as unless you exactly know the above procedure you may overwrite and thus destroy your files so a professional data recovery company is a serious consideration.

Computer virus’s are now numbering in the 100,000 + mark and another type of data loss situation maliciously designed with intent to destroy, overwrite or effect the logical integrity of the file these have been designed to destroy data in many instances up to date complete protection is required such as anti virus, anti spyware & malware and the relatively new root kit bugs, but all of this is of no use if it is not updated and system scan regularly.

Heat related issues are the no.1 killer of hard drive and the data they hold, hard drive cooling kits can prevent thermal issues impacting the operational performance of your hard disk and are readily available.

Probably the term head crash has been heard by many computer users and it has to be said is not always a qualified statement of fact.
Unusual noises emanating from the disk enclosure such as clicking and ticking noised do not automatically mean that a head crash has occurred in fact that noise can be from a number of failures such as head failure, preamplifier failure, servo fields and address markers not found, and firmware issues within the drive itself.
A head crash is when the heads come into direct contact with the surface of the platter(s) in an area and time they should not as some hard disks rest the head arrangement on the inside diameter of the disk when the drive is parked however if the heads come into contact with the surface elsewhere within the drive they may cause the condition of a head crash and score and damage the platter(s).
This type of failure can be catastrophic but depending on the company, tools and experience there may be a possibility of a recovery.

PCB or the printed circuit board is another area of failure and can cause a disk to fail and will require data retrieval it has been noted that some have tried swapping the PCB in an attempt to recover the data and unless this is done with exact knowledge and understanding of the specific manufacturer and model it should not be attempted as the PCB contains unique code embedded into it that pertains to that exact hard drive only and can not be swapped from another.The code on the PCB includes such issues as the head map arrangement, start up algorithm, and other such data unique to the media.
Typical reasons why users swap the PCB is that there is apparent chip damage which is clearly visible and usually this failed chip is the motor and or VCM voice coil motor chip which has blown.To successfully repair the printed circuit board you will need hot air rework stations, fine solder, a multimeter and above all else the very steady hand! Again if the data is of any value then expert opinion, advice and services must be sought, as in some instances if severe damage occurs to the PCB it can make the data unrecoverable.