The boot sector is a dedicated hard drive or other storage device containing the data used to start a computer system section. It includes the Master Boot Record (MBR), which is accessible during the boot sequence.
The boot sector is usually located at the beginning of a disc before the first partition. It includes the separation plan, which identifies all the partitions on the disk. It also defines the partition that contains the starting data (such as the operating system). This allows the computer knows how to access at boot partition. Therefore, if the boot sector of a disk becomes corrupted or contains invalid data, the computer may not be able to boot from the disc. If this happens, you must run a disk utility or antivirus to try to solve the problem.