KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q119429: ScanDisk Marks Valid Clusters Bad with Incorrect CMOS Settings

Article: Q119429
Product(s): Microsoft Disk Operating System
Version(s): MS-DOS:6.2,6.21,6.22
Operating System(s): 
Keyword(s): 
Last Modified: 20-NOV-1999

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft MS-DOS operating system versions 6.2, 6.21, 6.22 
-------------------------------------------------------------------------------

SYMPTOMS
========

When you perform a surface scan with ScanDisk, some valid, usable clusters are
designated as bad (unusable).

CAUSE
=====

This problem occurs if your CMOS settings are set incorrectly for your hard disk
drive. For example, if you have a 150-megabyte (MB) hard disk and the CMOS is
set for a 20-MB hard disk, ScanDisk scans the first 20 MB correctly, but the
remaining 130 MB are mark as bad.

RESOLUTION
==========

To correct your cluster entries:

1. Back up your files.

2. Correct your CMOS settings. (For more information, contact your hardware
  vendor.)

3. Run FORMAT /C /S to reformat the drive. (The /C parameter tells FORMAT to
  reexamine each cluster, and the /S parameter makes the drive bootable.)

  NOTE: Use the /S parameter only if the hard disk is your C drive.

4. Reinstall MS-DOS and Microsoft Backup.

5. Restore your data.


MORE INFORMATION
================

Running ScanDisk after you correct the CMOS settings does not correct the
problem. To avoid corrupting protection schemes that mark clusters bad, ScanDisk
does not change usable clusters marked as bad back to good.

Additional query words: 6.20 6.21 6.22 unused

======================================================================
Keywords          :  
Technology        : kbMSDOSSearch kbMSDOS621 kbMSDOS622 kbMSDOS620
Version           : MS-DOS:6.2,6.21,6.22

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.