====================================================================== Microsoft Product Support Services Application Note (Text File) PD0646: UPDATED CHKDSK.EXE AND UNDELETE.EXE FILES ====================================================================== Revision Date: 12/92 Disk Included The following information applies to Microsoft MS-DOS 5 Upgrade 5.0. -------------------------------------------------------------------- | INFORMATION PROVIDED IN THIS DOCUMENT AND ANY SOFTWARE THAT MAY | | ACCOMPANY THIS DOCUMENT (collectively referred to as an | | Application Note) IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY | | KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO | | THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A | | PARTICULAR PURPOSE. The user assumes the entire risk as to the | | accuracy and the use of this Application Note. This Application | | Note may be copied and distributed subject to the following | | conditions: 1) All text must be copied without modification and | | all pages must be included; 2) If software is included, all files | | on the disk(s) must be copied without modification [the MS-DOS(R) | | utility DISKCOPY is appropriate for this purpose]; 3) All | | components of this Application Note must be distributed together; | | and 4) This Application Note may not be distributed for profit. | | | | Copyright 1992 Microsoft Corporation. All Rights Reserved. | | Microsoft and MS-DOS are registered trademarks and Windows | | is a trademark of Microsoft Corporation. | -------------------------------------------------------------------- INTRODUCTION ------------ The Microsoft MS-DOS CHKDSK and UNDELETE commands dated 04/09/91, which are included in the Microsoft MS-DOS 5 Upgrade, do not work correctly on logical drives that require 256 sectors to store each copy of the file allocation table (FAT). If any of the partitions on your hard disk drive are within the ranges listed in the following section and you do not have version 5.0a of the Microsoft MS-DOS 5 Upgrade, which includes CHKDSK.EXE and UNDELETE.EXE files dated 11/11/91, install the updated CHKDSK.EXE and UNDELETE.EXE files included with this application note. If your FAT occupies 256 sectors, using the CHKDSK.EXE file dated 04/09/91 with the /f parameter ("chkdsk /f" [without the quotation marks]) can result in data loss. Using the UNDELETE.EXE file dated 04/09/91 can lead to unpredictable results. DETERMINING IF YOU NEED TO INSTALL THE UPDATED FILES ---------------------------------------------------- Drives require a 256-sector FAT if they have partitions within the size ranges listed below. Because the potential problems are serious, these ranges include a margin of safety. 127 MB-129 MB 254 MB-258 MB 508 MB-516 MB 1018 MB-1030 MB 2035 MB-2061 MB You can use the Fdisk program to determine if you have a 256-sector FAT with the following procedure: 1. At the MS-DOS command prompt, type the following and press the ENTER key: fdisk 2. Press 4 on the keyboard to select the Display Partition Information option and press ENTER. 3. The primary partition size is listed under the Mbytes heading. If the size falls within any of the ranges specified above, install the updated CHKDSK.EXE and UNDELETE.EXE files on the enclosed PD0646 disk. 4. If you have an extended partition, press the ENTER key to view those partition sizes. If any of the extended partition sizes listed under the Mbytes heading fall within the ranges specified above, install the CHKDSK.EXE and UNDELETE.EXE files on the enclosed PD0646 disk. 5. Press the ESC key twice to exit to the MS-DOS command prompt. TO REPLACE YOUR CHKDSK.EXE AND UNDELETE.EXE FILES ------------------------------------------------- 1. Insert the enclosed PD0646 disk in your floppy disk drive. 2. At the MS-DOS command prompt, type the following lines, pressing ENTER after each line copy drive:\chkdsk.exe destination copy drive:\undelete.exe destination where "drive" is the floppy disk drive containing the PD0646 disk and "destination" is the drive and directory where your CHKDSK.EXE and UNDELETE.EXE files currently reside. For example, if CHKDSK.EXE and UNDELETE.EXE are located in the DOS directory on drive C and the PD0646 disk is in drive A, you would type the following commands: copy a:\chkdsk.exe c:\dos copy a:\undelete.exe c:\dos