― Hard Disk Drive (HDD) or Solid State Drive (SSD) is the main storage unit of a Computer. When a data is copied to a HDD/SSD it is stored to tiny areas in its surface. So, even a minute damage or dirt in that area can render that data unreadable. By default, HDD/SSD marks such area/sector as bad, tries to read and copy the data (reallocate) to a spare area first and then redirects all access to that bad sector to the spare area. As such that bad sector cannot be accessed even by a complete drive [...].