Using Format with Floppy and Hard Disks

Format works in very different ways, depending on whether it is used on a hard or floppy disk. When Format is used on a hard drive, it creates a master boot record, two file allocation tables, and a root directory (also referred to as the root folder ). The rest of the drive is checked for disk surface errors ”any defective areas are marked as bad to prevent their use by the operating system. Format appears to "destroy" the previous contents of a hard disk, but if you use Format on a hard disk by mistake, Norton Utilities and some other programs can be used to unformat the drive and enable you to recover most, or even all, your information because most of the disk surface is not changed by Format.

The hard disk format process performed by the Format command (which creates the file system) is sometimes referred to as a high-level format to distinguish it from the low-level format used by hard drive manufacturers to set up magnetic structures on the hard drive. When floppy disks are formatted with the Full or Unconditional options, Format performs both a low-level and high-level format on the floppy disk surface.

If a floppy disk is prepared with Format and the unconditional /U option is used from the command line, or the Windows Explorer Full Format option is used, sector markings (a sector equals 512 bytes) are created across the surface of the floppy disk before other disk structures are created, destroying any previous data on the disk. If the Quick Format or Safe Format option is used, the contents of the disk are marked for deletion but can be retrieved with Norton Utilities or Norton System Works. For more information about using Format with hard drives , see Tables 15.5 and 15.6. For more information about using Format with floppy disks, see Table 15.7.

A floppy disk can be only a single drive letter, but a hard disk can be subdivided into one or more drive letters . Every drive letter created by Fdisk must be formatted.

Using Format with Floppy Drives

Although most floppy disks today are preformatted at the factory, Format is still useful as a means to

• Erase the contents of a floppy disk quickly, especially if it contains many files or folders.

• Place new sector markings across the disk.

• Create a bootable disk more reliably than by using the Sys command with a preformatted disk (Windows 9x only).

Table 15.7 covers the most important different Format options that apply to floppy disks. For additional Format options available with some versions of Windows, open a command-prompt window, type Format /? , and press Enter.

Table 15.7. Major Format Options for Floppy Drives

Command	Meaning	Used for	Example
Format x:/s	Formats x : drive with system (boot) files (not available with Me/2000/XP)	Makes a bootable floppy disk; assumes floppy disk is same capacity as the drive	Format A:/s
Format x:	Formats x : without system files	Erases the contents of a floppy disk; used for a data floppy disk	Format A:
Format A:/Q	Formats x : without scanning for bad areas; clears FAT and root directory	Erases the contents of a floppy disk; use only if disk is in good condition	Format A:
Format x:/u	Unconditionally formats the floppy disk; wipes out all previous data (not available with 2000/XP)	Rewrites the sector markings on an old floppy disk that might have developed weak areas; /u can be added to any other option	Format A:/s/u
Format x:/v	Allows user to add a volume label to the drive	Label can describe floppy disk's contents or be arbitrary text; can be added to any Format command	Format A:/s/v
Format x:/f:720	Formats a 720KB (DSDD) 3.5-inch disk in a 1.44MB (DSHD) drive [1]	Forces the drive to handle the 720KB floppy disk correctly; some IBM drives without media sensors will format 720KB media as 1.44MB media, but with poor reliability	Format A:/f:720
Format x: /f:360 or Format x:/4	Formats a 360KB (DSDD) 5.25-inch floppy disk in a 1.2MB (DSHD) drive [1]	Allows 1.2MB hard drives to create a floppy disk usable on a 360KB XT-style floppy disk drive; works well for new floppy disks, but might not reliably overwrite tracks made by a 360KB drive	Format B:/f:360 Format B:/4
Format x: and Format x:/s allow any existing data on the disk to be unerased with a program such as Norton Unformat . Format x:/f:360 and Format x:/f:720 are needed only when formatting disks that are not the default size of the drive, which is seldom necessary .

^[1] Other size options are also available in Windows 2000; the /f:size option is not supported in Windows XP .

Formatting Floppy and Hard Disks with Windows Explorer

Windows Explorer can be used to format both hard drives and floppy disks. Right-click the drive you want to format, select Format, and the Format options are displayed, as in Figures 15.17 and 15.18.

Figure 15.17. The Windows 9x Explorer Format menu enables the user to select the same options that can be used with the command-line Format program, and also provides an alternative to the Sys command.

Figure 15.18. The Windows XP Explorer Format menu for a floppy disk (left) and hard disk (right). Windows 2000 doesn't offer the Make an MS-DOS Startup Disk option, but is otherwise similar.

tip

To prepare for the A+ Certification Exam, you will find it useful to take a few blank floppy disks and practice the appropriate commands listed in Table 15.7 to help you memorize the command-line switches used.

The Windows Me Explorer Format has some of these same options, but lacks the option to create a bootable floppy. To create a bootable floppy with Windows Me, create an emergency startup disk, or copy the command.com and io.sys files from the \Windows\Command\EBD folder to a blank, formatted floppy disk.

The Windows XP Explorer Format options for floppy disk and hard disk can be seen in Figure 15.18. (Windows 2000's options are almost identical, except for the lack of the MS-DOS startup disk option.)