please dont rip this site
FORMAT + Formatting Disks

Prepares a disk by rearranging random magnetic impulses into

a series of tracks and sectors so that it is addressable by DOS.


PC-DOS 2.0+ (revised from 1.0)

MS-DOS equivalent: FORMAT (2.0+)




[d:][path] FORMAT



[d:][path] Specifies the drive letter and path that

contain the FORMAT command file.

fd: Specifies the disk to be formatted.

/S Transfers DOS files to the disk being


/1 Formats only one side of a double-sided


/8 Formats eight sectors per track instead

of nine (not for hard disks).

/V Writes a volume label on the disk.

Cannot be used with the /8 option.

/B Creates an eight sector per track disk

and reserves space for DOS without

transferring it.

/4 Formats a single- or double-sided disk

in a 1.2-megabyte high-capacity drive.

/N:xx Allows you to specify the number of

sectors per track to format.

/T:yy Allows you to specify the number of

tracks to format.

/H an undocumented switch that removes the "Insert new

diskette for drive x:" prompt. Be certain the correct

disk is in the drive before useing this switch as

formatting begins immediatly.



formats the disk in drive B.


places the DOS files on the disk in drive B as it formats it,

which makes the disk a system disk. To make the disk bootable as

well, copy COMMAND.COM onto it.


writes a volume label on the disk being formatted. You will be

prompted to enter a label. You can enter up to 11 characters.


formats the disk in drive B as a single-sided disk. For example,

you may be using a double-sided floppy drive but want to format a

disk so that it can be read by a single-sided drive.


formats the disk in drive A as a single-sided disk, eight sectors

per track. This makes the disk readable by a single-sided drive

using version 1 of DOS.


formats the disk in drive A without actually transferring DOS to

the disk but leaving room for it. You must use the SYS command to

write the system files on a disk formatted with the /B option.


Attempted write protect violation

The disk you are trying to format is write-protected. Remove the

write-protection or insert a new disk.

Bad Partition Table

The hard disk does not have a DOS partition, or the partition

table is invalid. Use FDISK to set up a new DOS partition and

then retry FORMAT.

Cannot find system files

The hidden files IBMBIO.COM and IBMDOS.COM could not be located

on the hard disk. Change to a drive that contains the system

files and try again.

Cannot FORMAT a Network drive

You cannot use the FORMAT command to format a network drive or a

drive on a computer that is being shared on a network. If your

computer is being shared, have the server pause and then issue

the FORMAT command.

Cannot format an ASSIGNed or SUBSTed drive

You cannot format a drive after an ASSIGN or SUBST command has

been used to reassign its designation. Issue the ASSIGN command

to restore the original drive assignments; then reissue the

FORMAT command.

Disk not compatible

The drive you specified is not supported by the IBM device

interfaces required by the FORMAT command. Use a different disk


Disk unsuitable for system disk

There is a defective track in the area that contains the DOS

files. Use this disk only for data; use a different disk to

contain DOS files.

Drive letter must be specified

Reissue the command with the drive letter of the disk to be


Error reading partition table

A hardware error probably occurred. Reissue the FORMAT command.

Error writing partition table

A hardware error probably occurred. Reissue the FORMAT command.

Format failure

The disk is unusable. Reissue the FORMAT command using another


Format not supported on drive n:

The disk device driver cannot handle certain calls. If you have

replaced the default disk device driver, remove it from your

CONFIG.SYS file and try again. If not, reinstall DOS on your boot

disk and try the FORMAT command again.

Invalid characters in volume label

You have used characters that are not valid. Retry, using valid


Invalid device parameters from device driver

The number of hidden sectors is not a multiple of the number of

sectors per track. Set up a new DOS partition by using FDISK;

then reissue the FORMAT command.

Invalid media or track 0 bad - disk unusable

Either track 0 is bad, in which case the disk is unusable, or the

disk and the drive are incompatible. Check the disk and drive; if

they are incompatible types, reissue FORMAT with the /4 option.

If they are compatible, use a new disk.

Parameter not compatible with fixed disk

You used the /1 or /8 options, neither of which can be used with

a hard disk. Reissue the command with the correct options.

Unable to write BOOT

The first track of the disk or the DOS partition is bad; the disk

is unusable. Get a different disk and try again.


If you format a disk that contained files you wish to

retain, you can use the Mace Utilities UnFORMAT command to

restore them, unless you are using a version of Compaq MS-DOS,

AT&T MS-DOS prior to version 3.1, or Burroughs MS-DOS.


No data can be stored on an unformatted disk. When a disk is

formatted, any data on it is erased. Version 2.0+ works with a

hard disk, formats nine sectors per track, and accepts a volume

label. Version 1.0 does not work with a hard disk. To avoid

inadvertently formatting a hard disk, thus erasing any and all

data on it, you can rename the FORMAT command and create a batch

file that gives you warning prompts when you use this command.


[For related topics, press R]


ASSIGN Command

BACKUP Command

CHKDSK Command

DIR Command


JOIN Command

LABEL Command

RENAME EN) Command

SELECT Command

SYS Command

VER Command

See also:

file: /Techref/dos/command/format.htm, 7KB, , updated: 2004/6/27 01:06, local time: 2017/10/18 09:54,

 ©2017 These pages are served without commercial sponsorship. (No popup ads, etc...).Bandwidth abuse increases hosting cost forcing sponsorship or shutdown. This server aggressively defends against automated copying for any reason including offline viewing, duplication, etc... Please respect this requirement and DO NOT RIP THIS SITE. Questions?
Please DO link to this page! Digg it! / MAKE! / 

<A HREF=""> dos command format</A>

After you find an appropriate page, you are invited to your to this massmind site! (posts will be visible only to you before review) Just type in the box and press the Post button. (HTML welcomed, but not the <A tag: Instead, use the link box to link to another page. A tutorial is available Members can login to post directly, become page editors, and be credited for their posts.

Link? Put it here: 
if you want a response, please enter your email address: 
Attn spammers: All posts are reviewed before being made visible to anyone other than the poster.
Did you find what you needed?

  PICList 2017 contributors:
o List host: MIT, Site host, Top posters @20171018 RussellMc, Van Horn, David, James Cameron, Sean Breheny, IVP, alan.b.pearce, Neil, David C Brown, Bob Blick, Denny Esterline,
* Page Editors: James Newton, David Cary, and YOU!
* Roman Black of Black Robotics donates from sales of Linistep stepper controller kits.
* Ashley Roll of Digital Nemesis donates from sales of RCL-1 RS232 to TTL converters.
* Monthly Subscribers: Gregg Rew. on-going support is MOST appreciated!
* Contributors: Richard Seriani, Sr.

Welcome to!