A bad sector is a term used to refer to a computer problem where data cannot be written onto a sector of the disk, cannot be accessed by the operating system or just cannot be used due to permanent damage. A sector is a segment or subdivision of a track on a magnetic or optical disk.

Bad sectors are generally detected by disk utility software such CHKDSK, SCANDISK and badblock. When these bad sectors are detected by utility software, they are blocked from usage and the operating system “skips” on them.

Data on hard disk bad sectors run the risk of getting corrupted and permanently destroyed

Modern operating systems map out a hard drive and avoid bad sectors so that they are not used even during reformatting. Furthermore, modern hard drives come with extra sectors to make up for those sectors which might go bad. This is a sort of buffering allowance in case of manufacture defects in hard disk sectors. When formatting a drive, the spare sectors are tapped to replace the bad sectors.

Data on hard disk bad sectors run the risk of getting corrupted and permanently destroyed. The causes of hard disk bad sectors are manufacturing defects in software or errors in the read/write heads which render the data on the sectors illegible. This is a rather mild case of bad sector which can be solved by a simple act of overwriting on and thereby completely erasing the disk data.

A more threatening case of bad sector is that due to mechanical errors as this kind rapidly breeds further bad sectors. A head crash is one example where the read/write head crashing on the surface of the platter sets off ripples of damage across the disk. As discussed above, spare sectors may replace the bad ones during formatting but if the bad sectors are yet propagating due to loose particles on the disk or some disk errors, the disk is still doomed to die soon.   It is urgent that data be salvaged as soon as possible before the disk finally expires, and that is where a data recovery professional such as Kingdom Data Recovery can help.