User's typical blunders

Frequent blunders resulting in increased cost and reduced efficiency of data recovery:

• Attempts to recover the file system using OS utilities (scandisk, checkdisk, etc.), or other third-party programs (Norton Disk Doctor, Partition Magic, etc.). Those utilities are for correcting the structure of file system rather than for user data recovery! They readily, often without any warnings, make unrecoverable changes in the data, basing on formal, often incorrect, data on file system structure rather than on the content of the user files. Those changes almost always result in lost important information, such as file allocation tables, folder structures, etc.
• Opening the HDD's Head and Disk Assembly (HDA) under inappropriate conditions without required experience and equipment. The result of such actions is dust in the HDA, which, in its turn, results in damaged magnetic heads and platter surfaces. A data track is less than 1 m in modern HDDs, and their heads fly at dozens of nms above the surface, that is why any work with HAD require high precision and special equipment.
• Attempts to work with a faulty device with possible writing on it. Writing on a device working abnormally may result in unpredictable, but always unwanted, consequences. This is true both for working with files when the file system is damaged and for attempts to hide bad sectors using widespread programs (mhdd, HDD regenerator, etc). For the first case, chances are high that the file system will deteriorate further, and for the second case, the HDD and user data are likely to be damaged more. In most cases, bad sectors are only the results of other faults, and attempts to remap them are similar to curing symptoms of a progressive disease. All that may result in damaged HDD service data (HDD's internal OS), or, in some cases, in serious damages in magnetic surface.