What is Bad Sector?
Bad sectors are areas on a hard disk that are physically damaged. The data present in these areas cannot be read with normal software, and no data can be stored there. All hard disks, including new ones, have bad sectors, which are a normal occurrence during the manufacturing process. The locations of the bad sectors are recorded by the hard disk circuitry, ensuring that they are avoided. However, bad sectors can also form during use, either as a result of improper shutdowns—causing the read / write head to physically scratch the recording surface—or due to normal wear and tear. Newly-developed bad sectors can also be recorded to ensure that they are not accessed the next time. This can be done by performing a “thorough” format of the drive.