Switching from DR-DOS 6.0 to MS-DOS 5.0 (80570)


The information in this article applies to:

  • Microsoft MS-DOS operating system 5.0
  • Microsoft MS-DOS operating system 5.0a
This article was previously published under Q80570

SUMMARY

Switching from DR-DOS 6.0 to MS-DOS 5.0 is accomplished much like you would switch from MS-DOS 4.x or 5.0 to another version of DOS. However, when switching from DR-DOS 6.0 to MS-DOS, some additional steps may be necessary IF:

  • The DR-DOS security system was used to safeguard the entire system. -or-

  • The DELWATCH utility was used.

MORE INFORMATION

System Security

When you use the DR-DOS Setup utility to install the DR-DOS security system, DR-DOS Setup does the following:

  • Adds a driver to the CONFIG.SYS file that asks for your password at bootup. If you do not enter the correct password, the system does not boot.
  • Changes the partition type of the DR-DOS partition(s). This is to prevent a user from booting MS-DOS on a floppy disk and accessing the drive.
However, the password can be disabled by editing the CONFIG.SYS file, however, the hard drive partition(s) will be inaccessible to MS-DOS unless you have removed the security option using DR-DOS Setup. If you have ever used this security option, do the following:

  • Use the DR-DOS Setup utility to remove the system security.
  • If you have disabled the utility by directly modifying the CONFIG.SYS file, use the DR-DOS Setup utility to re-enable and then disable system security.

DELWATCH

The DR-DOS 6.0 DELWATCH utility changes how DR-DOS implements deletions. Under MS-DOS (and non-DELWATCH DR-DOS) behavior, a file is deleted by marking the first character of a file with the "E5" character, and then marking the area of the disk that the file was stored "unused" in the file allocation table (FAT). DELWATCH marks the file as "pending delete" by changing the first character of the file to the "05" character. These files are not really deleted until the utility DELPURGE is used.

"Pending delete" files can cause confusion to MS-DOS and its utilities (such as CHKDSK and UNDELETE) as well as third-party disk utility programs. Before using MS-DOS, do the following:

  • Determine if you have "pending delete" files using the DR-DOS 6.0 CHKDSK utility.
  • If you load DELWATCH in the AUTOEXEC.BAT or CONFIG.SYS file, remove the DELWATCH command and reboot to disable DELWATCH.
  • Run DELPURGE immediately before booting MS-DOS or installing the MS-DOS 5 Upgrade.
The product included here, DR-DOS, is manufactured by vendors independent of Microsoft; we make no warranty, implied or otherwise, regarding this product's performance or reliability.
Modification Type:MajorLast Reviewed:9/30/2003
Keywords:KB80570
©2003 Microsoft Corporation. All rights reserved.