RESOLUTION

If MS-DOS won't read or format a high-density disk (1.2 megabyte [MB] or 1.44 MB), reconfigure your existing drive as described in Procedure 1. If you cannot read or format a low-density disk (360 kilobytes [K] or 720K) or a disk with an unusual configuration, read the "Problems with Other Disk Sizes" section later in this article before you try a solution.

IMPORTANT: Try Procedure 1 first. If it does not correct the problem, try Procedure 2.

Procedure 1: Reconfigure an Existing Drive

• Use a text editor, such as MS-DOS Editor, to open your CONFIG.SYS file. If you want to use MS-DOS Editor, type the following at the MS-DOS command prompt and press ENTER

edit <drive>:\config.sys

where <drive> is the startup drive where your CONFIG.SYS file currently resides. For example, if your startup drive is drive C, type the following command:

edit c:\config.sys


• At the end of the CONFIG.SYS file, add one of the following commands.

To get your first (or only) floppy disk drive to work with 1.2-MB (5.25-inch) disks, add the following line:

drivparm=/d:0 /f:1

To get your first (or only) floppy disk drive to work with 1.44-MB (3.5-inch) disks, add the following line:

drivparm=/d:0 /f:7 /i

To get your second floppy disk drive (if your computer has two) to work with 1.2-MB (5.25-inch) disks, add the following line:

drivparm=/d:1 /f:1

To get your second floppy disk drive (if your computer has two) to work with 1.44-MB (3.5-inch) disks, add the following line:

drivparm=/d:1 /f:7 /i


• Save your CONFIG.SYS file and exit the text editor. If you're using MS-DOS Editor, choose Exit from the File menu. When MS-DOS Editor displays a dialog box prompting you to save your file, choose the Yes button or press ENTER.
• Restart your computer by pressing CTRL+ALT+DEL.
• Try reading or formatting the floppy disk again.

If you can read or format the disk, you've corrected the problem and can stop here. If you still cannot read or format the disk, perform the next procedure.

Procedure 2: Create an Additional Logical Drive

If Procedure 1 did not correct the problem, do the following:

• Use a text editor, such as MS-DOS Editor, to open your CONFIG.SYS file. If you want to use MS-DOS Editor, type the following at the MS-DOS command prompt and press ENTER:

edit <drive>:\config.sys


• If you added a DRIVPARM command to your CONFIG.SYS file while following the first procedure, delete the DRIVPARM command.
• At the end of the CONFIG.SYS file, add one of the following DEVICE commands.

To get your first (or only) floppy disk drive to work with 1.2-MB (5.25-inch) disks, add the following line

device=<path>\driver.sys /d:0 /f:1

where <path> is the path to your DRIVER.SYS file. For example, if your DRIVER.SYS file is located in the DOS directory on drive C, type the following line:

device=c:\dos\driver.sys /d:0 /f:1

To get your first (or only) floppy disk drive to work with 1.44-MB (3.5-inch) disks, add the following line:

device=<path>\driver.sys /d:0 /f:7

To get your second floppy disk drive (if your computer has two) to work with 1.2-MB (5.25-inch) disks, add the following line:

device=<path>\driver.sys /d:1 /f:1

To get your second floppy disk drive (if your computer has two) to work with 1.44-MB (3.5-inch) disks, add the following line:

device=<path>\driver.sys /d:1 /f:7


• Save your CONFIG.SYS file and exit the text editor. If you're using MS-DOS Editor, choose Exit from the File menu. When MS-DOS Editor displays a dialog box prompting you to save your file, choose the Yes button or press ENTER.
• Restart your computer by pressing CTRL+ALT+DEL.

When your computer starts, MS-DOS displays a message stating that it has created a logical disk drive. This message includes the letter it has assigned to the new drive. For example, if you had drives A and C on your system before, this new drive is drive D, and MS-DOS displays the following message when you start your computer:


Loaded External Disk Driver for Drive D

• Insert a disk in the floppy disk drive and try formatting the disk using the new drive letter. For example, if the new drive is D, issue the FORMAT command using "d:" as the drive specification by typing the following at the MS-DOS command prompt and pressing ENTER:

format d:

If you still cannot format a floppy disk, you need to get updated hardware or software. If you used DRIVPARM or DRIVER.SYS successfully with your earlier version of MS-DOS, contact your computer manufacturer for a BIOS that supports MS-DOS 5.0 and later. If you have not used DRIVPARM or DRIVER.SYS before, you might need to get an updated version of your computer manufacturer's version of MS-DOS from your computer vendor.

Problems with Other Disk Sizes

If MS-DOS won't read or format a low-density disk (360K or 720K) or a 2.88-MB disk, you can follow the procedures outlined earlier in this article, but you must use a different value for the /F switch. The following table lists the /F switch values to use:

   Drive Size    Disk Capacity    Values to Use
   --------------------------------------------
   5.25-inch     160K, 180K,      /F:0
                 320K, 360K
   3.5-inch      720K             /F:2
   3.5-inch      2.88 MB          /F:9

For example, if you are having problems using a 720K disk drive, follow Procedure 1 or 2, but substitute /F:2 for the /F switch value shown in the procedure. When using DRIVPARM to specify drive parameters on a 3.5-inch disk drive, it may be necessary to use the /I (the letter "I") switch in addition to the /F switch. The /I switch is valid with DRIVPARM only and should not be used with DRIVER.SYS.

If you have a disk with an unusual configuration (a nonstandard number of heads or sectors, for example), you can specify additional switches with DRIVPARM or DRIVER.SYS. For more information, see the Microsoft MS-DOS 5.0 "User's Guide and Reference" or MS-DOS Help for version 6.0 or 6.2 (type help at the MS-DOS command prompt).