Insufficient Disk Space to Install MS-DOS 6.21 Upgrade (114358)

The information in this article applies to:
    Microsoft MS-DOS operating system 6.21
    Microsoft MS-DOS operating system 6.22

This article was previously published under Q114358


You run out of disk space when installing MS-DOS 6.21 over MS-DOS 6.0 or later or IBM PC DOS version 6.3.


When you install MS-DOS 6.21 on a system that has an existing copy of Microsoft Backup for MS-DOS or Microsoft Backup for Windows, you may get past the 4,200,000-byte minimum disk space check and subsequently run out of disk space during Setup. On a system with MS-DOS 6.0 or 6.2 installed with Backup for MS-DOS and/or Backup for Windows, the actual minimum free space required is 5,084,736 bytes.


To work around this problem, use the following steps when you receive the above error message:

    Exit Setup.
    Rename or delete MSBACKUP.EXE and MWBACKUP.EXE.
    Restart Setup.
This allows you to choose None for Backup and reduce the required free space to install MS-DOS.

Modification Type: Major Last Reviewed: 12/2/1999
Keywords: KB114358