Microsoft DOS format command

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About format
Availability
Syntax
Examples
Additional information

About format

Format is used to erase all of the information off of a computer diskette or fixed drive.

Availability

The format.com command is an external command that is available in the below Microsoft operating systems.

All Versions of MS-DOS
Windows 95
Windows 98
Windows ME
Windows NT
Windows 2000
Windows XP
Windows Vista
Windows 7

Syntax

Microsoft Windows 95, 98, ME syntax

Formats a disk for use with MS-DOS.

FORMAT drive: [/V[:label]] [/Q] [/F:size] [/B | /S] [/C]
FORMAT drive: [/V[:label]] [/Q] [/T:tracks /N:sectors] [/B | /S] [/C]
FORMAT drive: [/V[:label]] [/Q] [/1] [/4] [/B | /S] [/C]
FORMAT drive: [/Q] [/1] [/4] [/8] [/B | /S] [/C]

/V[:label]	Specifies the volume label.
/Q	Performs a quick format.
/F:size	Specifies the size of the floppy disk to format (such as 160, 180, 320, 360, 720, 1.2, 1.44, 2.88).
/B	Allocates space on the formatted disk for system files.
/S	Copies system files to the formatted disk.
/T:tracks	Specifies the number of tracks per disk side.
/N:sectors	Specifies the number of sectors per track.
/1	Formats a single side of a floppy disk.
/4	Formats a 5.25-inch 360K floppy disk in a high-density drive.
/8	Formats eight sectors per track.
/C	Tests clusters that are currently marked "bad."

Microsoft Windows 2000 and Windows XP syntax

Formats a disk for use with Windows 2000.

FORMAT volume [/FS:file-system] [/V:label] [/Q] [/A:size] [/C] [/X]
FORMAT volume [/V:label] [/Q] [/F:size]
FORMAT volume [/V:label] [/Q] [/T:tracks /N:sectors]
FORMAT volume [/V:label] [/Q] [/1] [/4]
FORMAT volume [/Q] [/1] [/4] [/8]

volume	Specifies the drive letter (followed by a colon), mount point, or volume name.
/FS:filesystem	Specifies the type of the file system (FAT, FAT32, or NTFS).
/V:label	Specifies the volume label.
/Q	Performs a quick format.
/C	Files created on the new volume will be compressed by default.
/X	Forces the volume to dismount first if necessary. All opened handles to the volume would no longer be valid.
/A:size	Overrides the default allocation unit size. Default settings are strongly recommended for general use. NTFS supports 512, 1024, 2048, 4096, 8192, 16K, 32K, 64K. FAT supports 512, 1024, 2048, 4096, 8192, 16K, 32K, 64K, (128K, 256K for sector size > 512 bytes). FAT32 supports 512, 1024, 2048, 4096, 8192, 16K, 32K, 64K, (128K, 256K for sector size > 512 bytes). Note that the FAT and FAT32 files systems impose the below restrictions on the number of clusters on a volume: FAT: Number of clusters <= 65526 FAT32: 65526 < Number of clusters < 268435446 Format will immediately stop processing if it decides that the above requirements cannot be met using the specified cluster size. NTFS compression is not supported for allocation unit sizes above 4096.
/F:size	Specifies the size of the floppy disk to format (160, 180, 320, 360, 640, 720, 1.2, 1.23, 1.44, 2.88, or 20.8).
/T:tracks	Specifies the number of tracks per disk side.
/N:sectors	Specifies the number of sectors per track.
/1	Formats a single side of a floppy disk.
/4	Formats a 5.25-inch 360K floppy disk in a high-density drive.
/8	Formats eight sectors per track.

Microsoft Windows 2000 and Windows XP recovery console syntax

Formats a disk for use with Windows 2000.

format [drive:] [/q] [/fs:file-system]

drive:	Specifies the drive to format.
/q	Performs a quick format.
/fs:file-system	Specifies the file system to use (FAT, FAT32, or NTFS)

Examples

When using the format command, remember all information on the drive you wish to format will be completely erased.

format a:

Would erase all the contents off a disk. Commonly used on a diskette that has not been formatted or on a diskette you wish to erase.

format a: /q

Quickly erases all the contents of a floppy diskette. Commonly used to quickly erase all information on the diskette.

format c:

This would erase all the contents of your C: hard disk drive. In other words, unless you wish to erase all your computer's information, this command should not be done unless you're planning to start over.

Additional information

Additional information about formatting your computer hard disk drive and starting over can be found on document CH000186.
Help with formatting a floppy diskette in MS-DOS can be found on document CH000727.

http://www.computerhope.com/formathl.htm