Microsoft KB Archive/66596

= Installing MS-DOS with Incorrect Disks for Drive A =

Article ID: 66596

Article Last Modified on 11/26/2003

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APPLIES TO


 * Microsoft MS-DOS 3.1
 * Microsoft MS-DOS 3.2 Standard Edition
 * Microsoft MS-DOS 3.21 Standard Edition
 * Microsoft MS-DOS 3.3 Standard Edition
 * Microsoft MS-DOS 3.3a
 * Microsoft MS-DOS 4.0 Standard Edition
 * Microsoft MS-DOS 4.01 Standard Edition
 * Microsoft MS-DOS 5.0 Standard Edition

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This article was previously published under Q66596



SUMMARY
If you have the Microsoft MS-DOS 5 Upgrade in the proper disk format for drive A or B, you can install it with no special steps. For more information, query on the following words in the Microsoft Knowledge Base:

which and drives and getting and started

If the MS-DOS 5 Upgrade is in the proper format for a floppy drive on your system, but not drive A or B, you may be able to make usable copies of the disks. For more information, query on the following words in the Microsoft Knowledge Base:

copy and different and size and msdos and upgrade

If you have Microsoft MS-DOS (not the Upgrade), it is recommended that you obtain the correct size disks for drive A. For more information, query on the following words:

get and correct and disk and size and msdos

It is possible, though, in most versions of MS-DOS, to install a new version of MS-DOS to the hard disk without booting the new version first. That is, if the disk format is correct for drive B but not drive A, installation may still be possible. See below for information about your particular situation.



MORE INFORMATION
In the following examples, it is assumed that MS-DOS version 3.2 is already installed on the hard drive. However, upgrading from MS-DOS version 3.21, 3.3, or later can be done in much the same way.

Upgrading to MS-DOS 3.21 or 3.3
Boot MS-DOS 3.2 from the hard disk. Place the program disk in drive B and change the default drive to drive B. The SYS command currently on the hard disk may now be able to transfer the system files from the floppy disk in drive B to a blank, formatted floppy disk in drive A. However, the boot sector on the floppy will be the version 3.2 boot sector, and therefore, the floppy may not be bootable. Use the SYS command on the floppy disk, not on the hard disk. For example, if the version 3.2 SYS.COM is located in the C:\DOS directory, use the following commands:

B:\>c:\dos\sys a:

B:\>copy command.com a:

Try to reboot the machine with the resulting boot disk. If the machine boots, you can install MS-DOS on the hard disk. If the CHKDSK command verifies that the new version of MS-DOS accesses the hard drive properly, you can place the Program disk in drive B and enter the following command:

B:\>sys c:

to transfer the new MS-DOS system files to the hard drive. Because the new version of SYS.COM is being used, the boot sector on the hard disk will be updated from version 3.2 as well. If the new version of MS-DOS does not access the hard drive properly, reformatting and/or repartitioning will be required.

Upgrading to MS-DOS 4.0 or 4.01
You can use the SYS.COM on the Install disk to transfer the system files to a floppy that can then be used to boot 4.0x. This technique can also be used to transfer the system files to the hard disk without booting MS-DOS 4.0/4.01; however, disk corruption can result if an OEM modified the method by which the previous MS-DOS version accesses the hard disk.

Because the MS-DOS version 4.0/4.01 SYS.COM is being used, it will update the boot sector on the floppy. To use the MS-DOS version 4.0/4.01 SYS command, type the following:

B:\>sys a:

Copy COMMAND.COM to the SYS[tem] disk and reboot from the resulting boot disk. If CHKDSK (located on the 5.25-inch Operating 1 disk or the 3.5-inch Operating disk) verifies that you can correctly access each hard drive, then you can use the SYS command to transfer the 4.0 system files to drive C. To do this, the Install disk should be in drive B, and the current drive must be B. Type the following command:

B>sys c:

Copy COMMAND.COM to drive C, delete the previous MS-DOS files, and copy the remaining MS-DOS 4.0 files to the DOS directory.

If 4.0 does not properly access the hard drive, you will have to repartition it.

For more information on how to manually install MS-DOS version 4.0, query on the following words:

prod(msdos) and select and manually and how

Additional query words: 3.2 3.20 3.3 3.30 3.3a 3.30a 4.0 4.00 4.01 4.01a 5.00 5.00a

Keywords: KB66596

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