MS-DOS 5.x and 6.x Install to Drive C Only (73410)

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 Q73410


MS-DOS Upgrade Setup makes the first primary partition on the first fixed disk the active partition and assigns it the letter C. This makes it the bootable partition.

As a result, MS-DOS Upgrade Setup cannot install MS-DOS files to a drive other than C.


If you have your MS-DOS files on a drive other than C, Setup reports the following (even if the directory that contains your MS-DOS files is not \DOS):

Setup has determined that your current DOS files are in the following directory:

If you have more than two floppy disk drives before upgrading, the drive letters assigned to the floppy disk drives will be the first available letters after all the logical drives on all the fixed disks have been named.

If a partition other than drive C was the active partition before the upgrade, the Setup program reassigns the partitions so that the first primary MS-DOS partition on the first physical hard disk drive is active.

This scheme standardizes the way MS-DOS is placed on the hard disk drive to enable developers to have a standard for writing installation programs. Programmers know that MS-DOS, by default, is installed on the C partition.

Modification Type: Major Last Reviewed: 5/10/2003
Keywords: KB73410