May 19, 2010

"format" Command

Format is used to erase all of the information off of a computer diskette or fixed drive. The command is an external command that is available in All Versions of MS-DOS, Windows 95, Windows 98, Windows ME, Windows NT, Windows 2000, Windows XP, Windows Vista and Windows 7.

Syntax - format [drive:] [switches]

  • /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.
  • /FS:FileSystem - Specifies the type of the file system (FAT, FAT32, or NTFS).
  • /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.
  • 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.