Formatting a floppy disk
Do not format a floppy disk at a size higher than it was designed for. For
example, do not format a 360K floppy disk at 1.2MB.
Also, if you use the FORMAT command without specifying the size of the
floppy disk, MS-DOS will format the floppy disk at the disk capacity of the
disk drive. Thus, if you format a floppy disk without specifying the size,
be careful not to use a floppy disk smaller than the capacity of the disk
Typing a volume label
After formatting a floppy disk, FORMAT displays the following message:
Volume label (11 characters, ENTER for none)?
The volume label can be a maximum of 11 characters (including spaces). If
you do not want your disk to have a volume label, press ENTER. For
information about volume labels, see the LABEL command.
Formatting a hard disk
When you use the FORMAT command to format a hard disk, MS-DOS displays a
message similar to the following before attempting to format the hard disk:
WARNING, ALL DATA ON NON-REMOVABLE DISK
DRIVE x: WILL BE LOST!
Proceed with Format (Y/N)?_
To format the hard disk, press Y; if you do not want to format the disk,
When formatting is complete, MS-DOS displays messages showing the total disk
space, any space marked as defective, the total space used by the operating
system (if you used the /S or /B switch), and the space available for your
If you do not specify the /U switch or a switch that reformats the disk to a
different size, FORMAT performs a "safe" format. It clears the file
allocation table and root directory of the disk but does not delete any
data. You can then use the UNFORMAT command to recover the disk if you did
not intend to format the disk. FORMAT also checks each sector on the disk to
ensure that the sector can properly store data. If it locates a sector that
cannot store data, FORMAT marks that sector to prevent MS-DOS from using
If you specify the /U switch or any switch that changes the size of the
disk, FORMAT performs an unconditional format by deleting all data on the
You can speed up the formatting process by using the /Q switch. Use this
switch only if you have not received read or write errors on your disk. You
can speed up the process even more by using both the /Q and /U switches. If
you use the /U switch, FORMAT does not save the information necessary to
later unformat the disk.
Formatting a new disk
When you use FORMAT to format a disk that has never been formatted, you can
specify the switches /U /C to reduce formatting time.
If you are using DriveSpace and don't often use compressed floppies, you
might also want to disable the AutoMount feature to further reduce
formatting time. To do this, use the <DRVSPACE /AUTOMOUNT> command, or turn
off the Automount option in the Options dialog (start DriveSpace, and then
choose Options from the Tools menu).
Using format with a SUBST drive or a network drive
You should not use the FORMAT command on a drive prepared by using the SUBST
command. You cannot format disks over a network or an Interlnk drive.
FORMAT exit codes
The following list shows each exit code and a brief description of its
0 The format operation was successful.
3 The user pressed CTRL+C or CTRL+BREAK to stop the process.
4 A fatal error occurred (any error other than 0, 3, or 5).
5 The user pressed N in response to the prompt "Proceed with Format
(Y/N)?" to stop the process.
You can check these exit codes by using the ERRORLEVEL condition with the IF
batch command. For an example of a batch program that supports ERRORLEVEL
conditions, see the <CHOICE> command.