Floppy Disk is Not Accessible, Not Formatted, or Not Recognized by Windows (140060)
The information in this article applies to:
- Microsoft Windows NT Advanced Server
- Microsoft Windows NT Server 3.1
- Microsoft Windows NT Workstation 3.1
- Microsoft Windows NT Workstation 3.5
- Microsoft Windows NT Workstation 3.51
- Microsoft Windows NT Workstation 4.0
- Microsoft Windows NT Server 3.5
- Microsoft Windows NT Server 3.51
- Microsoft Windows NT Server 4.0
- Microsoft Windows 98
- Microsoft Windows 98 Second Edition
- Microsoft Windows Millennium Edition
- Microsoft Windows 2000 Advanced Server
- Microsoft Windows 2000 Datacenter Server
- Microsoft Windows 2000 Professional
- Microsoft Windows 2000 Server
- Microsoft Windows XP 64-Bit Edition
- Microsoft Windows XP Home Edition
- Microsoft Windows XP Media Center Edition
- Microsoft Windows XP Professional
- Microsoft Windows XP Tablet PC Edition
- Microsoft Windows Server 2003, 64-Bit Datacenter Edition
- Microsoft Windows Server 2003, 64-Bit Enterprise Edition
- Microsoft Windows Server 2003, Datacenter Edition
- Microsoft Windows Server 2003, Enterprise Edition
- Microsoft Windows Server 2003, Standard Edition
- Microsoft Windows Server 2003, Web Edition
- Microsoft Windows Small Business Server 2003, Premium Edition
- Microsoft Windows Small Business Server 2003, Standard Edition
This article was previously published under Q140060 SYMPTOMS When you access a floppy disk, you may receive one of the
following error messages: A:\ is not accessible. The
device is not ready. Disk is not formatted The disk in drive
A is not formatted. Do you want to format it now? STOP: The disk media is not recognized, it
may not be formatted. The same disk may work correctly with MS-DOS or
Windows 95, or after you re-format the disk with Windows 98, Windows Millennium
Edition, Windows NT, Windows 2000, Windows XP, or Windows Server
2003. CAUSE This problem occurs on disks that do not contain a media
descriptor byte in the BIOS parameter block (BPB) of the boot sector. Some
older preformatted floppy disks do not contain a media descriptor byte. Older
product disks may also not have the media descriptor byte.
The media
descriptor indicates the type of medium currently in a drive. With MS-DOS and
Windows 95, you do not have to set the media descriptor byte. Therefore this
problem does not occur with these older operating systems.
The media
descriptor byte is located in the BPB of the boot sector at offset 21 (15h) and
in the first byte of each FAT on the disk.RESOLUTIONTo resolve this problem, re-format the floppy disk with
Windows 98, Windows Millennium Edition, Windows NT, Windows 2000, Windows XP,
or Windows Server 2003.WORKAROUNDWarning: This workaround is for advanced users only. This workaround
involves using a disk sector editor to modify the media descriptor byte on the
floppy disk. Misuse of a disk sector editor may make all the data on the drive
or volume permanently inaccessible. Disk sector editors function at a level
"below" the file system, so the typical checks for maintaining disk consistency
do not apply. This provides you direct access to every byte on the physical
disk regardless of access credentials. Therefore, you can damage or permanently
overwrite critical on-disk data structures. Use this workaround at your own
risk. To work around this problem, use a disk sector editor to change
the BPB media descriptor byte to the appropriate value. For example, you can
use the DiskProbe tool to do this on a Windows NT 4.0-based, Windows
2000-based, Windows XP-based, or Windows Server 2003-based computer. DiskProbe
(Dskprobe.exe) is included with the Windows Support Tools for Windows XP
Professional and Windows XP 64-Bit Edition, the Windows 2000 Support Tools, and
Windows NT 4.0 Resource Kit Support Tools. The following table lists
the most common media descriptor bytes:
Byte Capacity Media Size and Type
-------------------------------------------------
F0 2.88 MB 3.5-inch, 2-sided, 36-sector
F0 1.44 MB 3.5-inch, 2-sided, 18-sector
F9 720K 3.5-inch, 2-sided, 9-sector
F9 1.2 MB 5.25-inch, 2-sided, 15-sector
FD 360K 5.25-inch, 2-sided, 9-sector
FF 320K 5.25-inch, 2-sided, 8-sector
FC 180K 5.25-inch, 1-sided, 9-sector
FE 160K 5.25-inch, 1-sided, 8-sector
FE 250K 8-inch, 1-sided, single-density
FD 500K 8-inch, 2-sided, single-density
FE 1.2 MB 8-inch, 2-sided, double-density
F8 ----- Hard disk
The BPB media descriptor byte is located in sector 0 of the disk,
and looks similar to this:
addr data:
0000 EB 3C 90 4D 53 44 4F 53 35 2E 30 00 02 01 01 00
0010 02 E0 00 40 0B F0 09 00 12 00 02 00 00 00 00 00
xx <---- This byte above XX is the media descriptor
byte and is at offset hexadecimal 21 (15h).
Modification Type: | Minor | Last Reviewed: | 12/16/2004 |
---|
Keywords: | kbother KB140060 |
---|
|