MBR

Short for Master Boot Record, MBR is also sometimes referred to as the master boot block and is the first sector of the computer hard disk drive used to determine what partition a computer will boot. The MBR tells the computer where to find and how to load the operating system. It also tells the computer how the hard drive is organized and provides information about the drive's partitions. 

The master boot record is located on the first sector of the hard drive; it's the first program the computer runs after performing a memory check and looking for a bootable disk (if set in CMOS). The MBR is also susceptible to boot sector viruses that can corrupt or delete the MBR, which can leave the hard drive unusable and prevent the computer from booting up. A well-known MBR virus is the Stone Empire Monkey Virus.

• Additional information about the FDISK /MBR can also be found on document CH000175.
• Information about the Stoned Empire Monkey Virus can be found here.

Also see: Bootstrap loader, Hard disk drive definitions