High Level Formatting

The second formatting step is high-level formatting. This is the process of creating the disk's logical structures such as the file allocation table and root directory. The high-level format uses the structures created by the low-level format to prepare the disk to hold files using the chosen file system.

Method of formatting a hard disk drive that initializes portions of the hard disk drive and creates important file system areas on the disk. A good example of a high-level format is using the format command in MS-DOS.

A high-level format is commonly done if a user wishes to erase the hard disk drive and reinstall the operating system back onto the hard disk drive. If errors are present on the hard disk drive, or a high-level format is unable to be completed, a low-level format may need to be done first.

For a hard disk, there is an intermediate task that is performed between the two formatting steps: partitioning. For this reason, combined with the incredible complexity of modern hard disks, they are low-level formatted by the manufacturer, and high-level formatting is done by the DOS FORMAT command (or equivalent). Floppy disks require no intermediate step, and due to their relative simplicity, they are both low-level and high-level formatted at the same time by default when you use the FORMAT command.