MS-DOS Upgrade Detects DOS Path as D: \DOS with Stacker (74307)

The information in this article applies to:
    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 Q74307


The MS-DOS 5 or later Upgrade and MS-DOS 6.2 Step-Up should not be used to upgrade a primary DOS partition being compressed by Stacker. The upgrade identifies the DOS path as D:\DOS. There is no way to change the drive letter. When setup is complete, the disk will not be bootable.


Stacker works by creating a file named in the root directory of the drive to be compressed. Stacker then creates a new drive that is contained within that file. When you access the new Stacker volume, the Stacker program compresses and decompresses data to and from the file stored in the root of the compressed drive.

Typically, the MS-DOS 5 upgrade will report that there is not enough free disk space to install in a Stacker volume. The Setup program is not fooled by the SSWAP.COM program; Setup finds the real primary DOS partition, even if it has been swapped to the D drive, and checks the free space. Typically, there is little free space on this drive due to the file.


The following procedure will upgrade a system using Stacker on the D drive:

    Install the MS-DOS Upgrade to floppy disks.
    Run SYS on the drive that was the C drive at boot time.
    Copy COMMAND.COM to the drive that was the C drive at boot time.
    Copy IO.SYS, MSDOS.SYS, and COMMAND.COM to the Stacker volume.
    Copy all files from the floppy disks to the C:\DOS subdirectory on the Stacker volume.
NOTE: If you are using MS-DOS 5.0 or later you can skip step 3 as SYS copies COMMAND.COM automatically.

You may also want to set the attributes on MSDOS.SYS and IO.SYS to hidden files.

The product included here is manufactured by vendors independent of Microsoft; we make no warranty, implied or otherwise, regarding this product's performance or reliability.

Modification Type: Major Last Reviewed: 5/12/2003
Keywords: KB74307