PC Review has posted an article on Hard Drive Data Recovery

One of the most important points for any computer user to remember is to always back up your data. As much as personal computing has advanced over the past 20 years, hard drives still fail. Hard Drives are an amazing piece of mechanical engineering, as then spin (sometimes continuously) at around 120 times per second (7200 rpm). These spinning platters are spinning at such high speeds that a small interference whilst in usage can damage the disk in a certain area. There are now fail safe mechanisms in place to prevent critical failures when there is a small amount of physical damage done to the drive, but accidents do happen.

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