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.
• The DELWATCH utility was used.
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
• 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
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.
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
• 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.