Wyse DOS 3.3 Partitions Incompatible with MS-DOS 5.x and 6.x (78407)

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 Q78407


When upgrading to MS-DOS 5.0 or later from Wyse DOS version 3.3 or earlier, the following message may be displayed:

Incompatible Drive or Device Driver


If this error occurs, the partitions created by Wyse DOS must be deleted from the hard disk and the MS-DOS 5 or later Upgrade must be installed manually.


Partitions created by Wyse DOS 3.3 or earlier are not compatible with MS-DOS 5.0 because of the logical sectoring. Some original equipment manufacturers (OEMs) modified their adaptations of MS-DOS to provide logical drives larger than 32 MB in versions of MS-DOS earlier than version 4.0. This was usually implemented by using a sector size larger than the standard value of 512 bytes. This is called "logical sectoring" because the sector size of the drive is a logical value; that is, it is dependent on the value in the BIOS parameter block of the drive for bytes per sector. Microsoft MS-DOS versions 4.0 and later do NOT support this logical sectoring on hard drives. A sector size of 512 bytes per sector is assumed on all hard drives.

For more information on repartitioning the hard disk, see Chapter 4 of the version 5.0 "Microsoft MS-DOS Getting Started" guide, or query on the following words:

partition and format

For more information on manual installation, query on the following words:

manual and install

According to Wyse, Wyse DOS 5.0 is not different from MS-DOS 5.0; it also will not recognize partitions created by Wyse DOS 3.3. The products included here are manufactured by vendors independent of Microsoft; we make no warranty, implied or otherwise, regarding these products' performance or reliability.

Modification Type: Major Last Reviewed: 5/10/2003
Keywords: KB78407