Disk Sectors Critical to Startup

The two sectors critical to starting your computer are the master boot record (MBR), which is always located at sector 1 of cylinder 0, head 0, the first sector of a hard disk, and the boot sector, which resides at sector 1 of each volume. These sectors contain both executable code and the data required to run the code.

Note

The use of basic or dynamic disk does not affect where the MBR is located on disk and only minor differences exist between the two for how the partition table is configured. However, as the Disk Management database contains the information where dynamic volumes begin and end, the method of walking, or navigating, partition tables to find the start and end of partitions and logical volumes, as well as finding volume boot sectors, does not work on dynamic disks. Disk editing tools, such as DiskProbe and third-party tools, can walk the partitions as expected with basic disks. Also, many disk editor tools that work with Windows NT and NTFS are not currently compatible with FAT32 boot sectors and volumes.

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