Examples of bad and good practices of data recovery from a damaged disk

A classic example of bad and good practices in data recovery:

The customer has a drive, which sometimes make strange noises, the computer occasionally freezes, and the data can not be copied.

Good practice:

The computer was turned off immediately, the disk was sent to our laboratory that is equipped with a special device allowing access to the disc in a manufacturer mode

1. read and backed up service partition
2. diagnosed a malfunction of one of the four reading heads, physically damaged surface of data plates detected
3. a map of the disc delineating areas occupied by different heads established
4. faulty head deactivated, sectors relevant to healthy heads cloned to a backup disk, the areas with damaged surface omitted
5. disk opened in a dust-free room, reading heads removed and replaced with new ones
6. modified parameters of disk’s firmware to accept the new heads
7. reading the sectors of the remaining defective heads
8. unread sectors on the backup disk replaced with a sector enabling later identification of damaged files
9. reconstruction of the file system, copying of the retrieved data

97% of data successfully recovered

Bad practice:

Disk handed over to a friend’s son who has been a computer fan for a few years, he will surely be able to deal with it.

1. disk connected via USB to a functioning computer, repeated attempts to read files
2. disk drive makes strange noises increasingly more often, several files were able to be copied
3. disk only makes noise, is not detectable
4. disk submitted to our laboratory for analysis
5. major physical damage of the surface of data plates diagnosed
6. identified destruction of reading heads due to contact with the damaged surface
7. destroyed reading head made a groove in the area of disk’s service tracks 

Data recovery is not possible