An MBR (master boot record), or also referred to as the first partition sector, is a 512-byte boot sector that is the first sector (LBA Sector 0) of a partitioned hard drive. Consequently the master boot record becomes a target for boot-sector infecting viruses. In addition to the bootstrap code and a partition table the master boot record also contains a Windows signature. Fdisk has an undocumented parameter called /mbr that causes it to write the master boot record to the hard disk without altering the partition table information. Warning: Writing the master boot record to the hard disk in this manner can make certain hard disks partitioned with multi-boot utilities unusable. This first sector of the hard disk is called the master boot record (or sometimes the partition table or master boot block). This program is written to the disk by the fdisk /mbr command and is usually called the MBR. During normal operations, Fdisk writes this information to the disk only if there is no master boot record. During the installation of Microsoft MS-DOS, setup replaces the MBR on the hard disk with code to display a message MS-DOS.
Master Boot Code
Master Boot Code: The master boot record contains the small initial boot program that BIOS loads and executes to start the boot process. The MBR also contains the Master Partition Table. This small table contains the descriptions of the partitions that are contained on the hard disk. Due to the great importance of the information stored in the master boot record and if it were ever become damaged in some way the hard disk will no longer be accessible and serious data loss would result. Repairing the master boot record on your Windows XP system is accomplished using the fixmbr command, available in Recovery Console. This is necessary when the master boot record has become corrupt due to a virus or some other kind of damage. The MBR is created when you create the first partition on the hard disk which the most important data information on the disk.
Computer Startup
During the computer startup and when the hard drive is accessed the MBR points to the system partition’s starting location on the disk, and loads a copy of its Partition Boot Sector into memory. The MBR then transfers execution to executable code in the Partition Boot Sector. Special Note: Although there is a Master Boot Record on every hard disk, the executable code in the sector is used only if the disk is connected to an x86-based computer and the disk contains the system partition. The partition table is located in the master boot record on the disk.
Computer Boot Information
Master Boot Record has important computer boot information that contains all required information on how to boot the disk and load the operating system. MBR record is very important data for your computer and without this information, your computer will not be able to get to the starting point to load the operating system. The MBR is located in the Boot Sector of a hard drive. MBR is a hidden area on your hard drive that contains all information about disk partitions (sometimes also called volumes or logical drives).
Fdisk MBR
The Fdisk MBR website has additional articles that you might find useful.
