Bad Sectors

As all we know that a hard drive is made of the millions of sectors and it is possible that some of these sectors gone bad.As I a want to told you that when a hard drive is manufactured it still contains some bad sectors and as the life span of hard drive's increase or it gets old the number of bad sectors increased in it.A sector is a small area on the surface of the hard drive or a floppy disk.As all we know that each hard drive have several platters.The platters are the disc that are covered with magnetic material which is used to hold data and they are divided into a number of concentric rings known as track.If we talk about a floppy disk(1.44 MB) than it contains only one platter and having about 160 tracks.But in the case of hard drive it contains a lot of tracks and each track is divided into smaller storage areas called sectors.Now when a sector goes bad the whole data that it contains lost and it cannot be recovered.Bad sectors never affects the data of the remaining hard disk and disk is still completely usable.The main problem with the bad sectors is that it cannot be repaired,it only marked as unusable.Once you marked these bad sectors as unusable then operating system will never store data in these areas and storage capacity of your hard drive is decreased.