Effects of FDISK on Boot Record, Root Directory, and FATs (73736)


The information in this article applies to:

  • Microsoft MS-DOS operating system 3.1
  • Microsoft MS-DOS operating system 3.2
  • Microsoft MS-DOS operating system 3.21
  • Microsoft MS-DOS operating system 3.3
  • Microsoft MS-DOS operating system 3.3a
  • Microsoft MS-DOS operating system 4.0
  • Microsoft MS-DOS operating system 4.01
  • Microsoft MS-DOS operating system 5.0
  • Microsoft MS-DOS operating system 5.0a
  • Microsoft MS-DOS operating system 6.0
  • Microsoft MS-DOS operating system 6.2
  • Microsoft MS-DOS operating system 6.21
  • Microsoft MS-DOS operating system 6.22
This article was previously published under Q73736

SUMMARY

If you use MS-DOS FDISK to delete and then recreate a partition or logical drive on your hard disk, the boot record, root directory, and file allocation tables (FATs) of these logical drives may be affected in varying degrees, depending on the particular version of FDISK used.

MORE INFORMATION

MS-DOS Version 3.2

   Area                Effect
   ----                ------
   Boot record         Preserves boot record.
   Root directory      Preserves root directory.
   1st copy of FAT     Preserves 1st copy of FAT.
   2nd copy of FAT     Preserves 2nd copy of FAT.

MS-DOS Version 3.21

   Area                Effect
   ----                ------
   Boot record         Zeros area formerly occupied by boot record.
   Root directory      Zeros area formerly occupied by root directory.
   1st copy of FAT     Zeros area formerly occupied by 1st copy of FAT.
   2nd copy of FAT     Zeros area formerly occupied by 2nd copy of FAT.

MS-DOS Version 3.30a

   Area                Effect
   ----                ------
   Boot record         Fills area formerly occupied by boot record
                       with bytes containing value F6.
   Root directory      Fills area formerly occupied by root directory
                       with bytes containing value F6.
   1st copy of FAT     Fills area formerly occupied by 1st copy of FAT
                       with bytes containing value F6.
   2nd copy of FAT     Fills area formerly occupied by 2nd copy of FAT
                       with bytes containing value F6.

MS-DOS Version 4.01a

   Area                Effect
   ----                ------
   Boot record         Fills area formerly occupied by boot record
                       with bytes containing value F6.
   Root directory      Invalidates root directory; may contain
                       "garbage" values.
   1st copy of FAT     Invalidates 1st copy of FAT; may contain
                       "garbage" values.
   2nd copy of FAT     Invalidates 2nd copy of FAT; may contain
                       "garbage" values.

MS-DOS Versions 5.0 and 6.0

   Area                Effect
   ----                ------
   Boot record         Fills area formerly occupied by boot record with
                       bytes containing value F6.
   Root directory      Preserves root directory information.
   1st copy of FAT     Preserves 1st copy of FAT.
   2nd copy of FAT     Preserves 2nd copy of FAT.
Modification Type:MajorLast Reviewed:5/12/2003
Keywords:KB73736
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