Microsoft KB Archive/70559

Which Drives Can Be Used to Install MS-DOS 5.0? PSS ID Number: Q70559 Article last modified on 02-16-1993 PSS database name: O_MSDOS

5.00

MS-DOS

The information in this article applies to:

- Microsoft MS-DOS operating system version 5.00

Question:

Page 7 of the version 5.0 “Microsoft MS-DOS Getting Started” guide states that I should insert Disk 1 in drive A, but also states, “You can use a different disk drive if you want.” The next page specifies that the Uninstall disk(s) must be inserted in drive A. Exactly which disks can be in drive B? Which must be in drive A? Why?

Response:

When installing to a hard disk, the Microsoft MS-DOS 5 Upgrade can be installed from drive A or B and the hard drive(s) can be backed up to drive A or B. Floppy drives other than A or B cannot be used.

The Uninstall disk(s) must be created in drive A because the Uninstall #1 disk is designed to boot the machine in the event of an emergency. Should the installation process fail, the hard disk will probably be in a nonbootable state. The Uninstall #1 disk will allow you to boot and to either continue installation or to uninstall back to the previous version of MS-DOS.

Although a few machines allow you to boot from drive B, most machines are based on the IBM ROM BIOS standard and will boot only from drive A or from the hard drive.

When creating a set of MS-DOS version 5.0 working disks using the SETUP /F command (setup to floppies), the options are numerous. The MS-DOS installation disks can be placed in either drive A or B and the working disks can be created in drive A or B. The MS-DOS installation disks and working disks can use one drive, or one drive can be used for the installation disks while the other is used to create working disks. For example, you can insert the MS-DOS installation disks in drive B and the working disk(s) in drive A, or vice versa. Working disks can be formatted or unformatted.

Because most machines will not boot from drive B, you must be sure that the working disks can be used in drive A.

The number of working disks and the amount of information on each is determined by the type of MS-DOS distribution disks. If installing from 360K MS-DOS disks, about 360K of information will be written to each of seven disks. If installing from 720K disks, about 720K of information will be written to each of four disks. The working disks cannot be of a lesser capacity than the MS-DOS distribution disks.

Microsoft MS-DOS 5.0 (not the Upgrade) must be installed from drive A because you must boot off of the MS-DOS Disk 1.

Additional reference words: 5.00 noupd

Copyright Microsoft Corporation 1993.