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Runs Microsoft Backup for DOS, which backs up or restores one or more files from one disk onto another.

Note: DOS also includes Microsoft Backup for Windows. Depending on the choices you made during DOS Setup, you might have Backup for DOS, Backup for Windows, both, or neither. This topic explains only Backup for DOS; for information about Backup for Windows, see the DOS User's Guide.

You can back up all files on a disk or files that have changed since your last backup, schedule backups so they are done automatically on a regular basis, and restore files that you have backed up.


MSBACKUP [setup_file] [/T [D | I | F]] [/BW | /LCD | [/MDA]

setup_file (v6.0 Win95 ONLY)
Specifies the setup file that defines files to back up and the type of backup you want to perform. MSBACKUP creates a setup file when you save program settings and file selections. Setup files must have an SET extension. If you do not specify a setup file, MSBACKUP uses DEFAULT.SET.

/BW (v6.0 Win95 ONLY)
Starts MSBACKUP using a black-and-white color scheme.
/LCD (v6.0 Win95 ONLY)
Starts MSBACKUP using a video mode compatible with laptop displays.
/MDA (v6.0 Win95 ONLY)
Starts MSBACKUP using a monochrome display adapter.
( /T[D|I|F] v6.0)
UNDOCUMENTED. Backup type: Differential (all changed files since last FULL backup), Incremental (all changed files since last INCREMENTAL or FULL backup), or Full (all files)?



Must start MSBACKUP from a hard disk

MSBACKUP program files must be located on your hard disk. You cannot start MSBACKUP from a floppy disk.

Backup catalogs

As part of the backup process, MSBACKUP creates a backup catalog that contains information about the files you backed up. When you need to restore one or more files, you can load the backup catalog and easily select files from a backup set. The backup catalog includes information about the:

MSBACKUP gives each catalog file a unique name that helps you identify a backup set. Each character in the catalog name contains information about a particular backup set. For example, consider a typical catalog name such as CD20823A.FUL. Reading left to right, the character(s) in the filename mean:

You can easily locate the catalog for a backup set by using the information contained in the catalog filenames, even if you have many catalog files in your directory.

Each time you perform a full backup using a specific setup file, MSBACKUP creates a master catalog. The master catalog keeps track of all the backup catalogs made during the backup cycle. When the next full backup is performed and a new backup cycle begins, a new master catalog is created.

The master catalog is used if you need to restore a complete backup cycle. When you load the master catalog, the catalogs of all the backups that were created during the backup cycle are automatically merged. Then the latest version of each backed-up file can be automatically restored (or you can choose to restore an earlier version).

You can choose whether you want to keep all of the old catalogs or only the current catalogs on your hard disk. The catalogs will remain part of your backup sets.

When you back up files, MSBACKUP places one copy of the backup catalog on your hard disk, and a second copy on the disk or network drive that contains your backup set.

Restoring backups created by DOS 6 or 6.2 Backup programs

v6.22 Backup uses a different backup compression format from v6.0 and v6.2. Backup. The v6.22 Backup programs use the DriveSpace compression format; earlier Versions of Backup used the DoubleSpace compression format instead.

Because of this, v6.22 Backup for Windows cannot restore compressed backups created by v6.0 or v6.2 Backup.

v6.22 Backup for DOS can restore earlier compressed backups only if one of the conditions is true:

Both the Windows and DOS Versions of v6.22 Backup can successfully restore v6.0, v6.2 and v6.21 backups made without backup data compression. If you unchecked the Compress Backup Data box in the Backup Options dialog before you backed up, you should have no problems restoring your data using the v6.22 Backup programs.

If you try to restore an older compressed backup and Microsoft Backup displays an error message, you need to use the v6.0 or v6.2 Versions of Backup instead. If you do not currently have one of these Versions of Backup on your computer, you will need to retrieve the older version of Backup from your DOS 6x distribution disks. For more information, see Section 5.5.

Restoring backups made by using the BACKUP.EXE program

Neither MSBACKUP.EXE nor MWBACKUP.EXE can restore backups made by using the BACKUP.EXE program that came with v5.0 and earlier. For information about restoring such backups, see the RESTORE command.

Exchanging backups with DOS 6, 6.2, or 6.21 systems

If you plan to use either MSBACKUP.EXE or MWBACKUP.EXE to exchange backup files with other DOS 6.x systems, you should disable backup compression before backing up. In the Backup dialog, select the Options button, clear the Compress Backup Data check box, and select OK.

Insufficient memory

If you receive a message stating that you have insufficient memory, do:

  1. Make sure you have at lease 512K of memory on your computer.
  2. Quit MSBACKUP, remove all memory-resident programs from memory, and try using MSBACKUP again.
  3. Choose the Options button on the Backup screen to display the Disk Backup Options dialog box. Turn off the Compress Backup Data option and then choose OK.

The MSDOSDATA environment variable

Backup for DOS uses the %MSDOSDATA% environment variable to determine the location of configuration information, backup sets, and catalogs. Backup for DOS first searches for the MSDOSDATA environment variable. If this environment variable is not defined, the program searches the directory from which you started the program. If the program does not find the file, the program creates it using default values and places it in the directory.

The %MSDOSDATA% environment variable is useful if you share the Backup for DOS program files with others, but use your own configuration. For example, suppose the program files are located on drive P, a read-and-execute-only network server, and you want to use your own configuration, backup sets, and catalogs. To specify that Backup for DOS use the configuration information, backup sets, and catalogs located in the BACKUP directory on your drive C, add the line to your AUTOEXEC.BAT file:

    SET msdosdata=C:\BACKUP

To start Backup for DOS, type:


Changes you make to the configuration of Backup for DOS are saved in the BACKUP directory on drive C.


Suppose you created a setup file named WEEKLY.SET that defines a weekly full backup procedure on specified files. To use this setup file, type:




v6.0 v6.10 v6.2 v6.21 v6.22 v6.23 v7.00 v7.0R1
Windows NT