Associates a path with a drive letter. Used without parameters, subst displays the names of the virtual drives in effect.


subst [drive1: [drive2:]Path]

subst drive1: /d


drive1: : Specifies the virtual drive to which you want to assign a path.

drive2: : Specifies the physical drive that contains the specified path (if different from the current drive).

Path : Specifies the path that you want to assign to a virtual drive.

/d : Deletes a virtual drive.

/? : Displays help at the command prompt.


  • The following commands do not work, or should not be used, on drives used in the subst command:

    • chkdsk

    • diskcomp

    • diskcopy

    • format

    • label

    • recover

  • The drive1 parameter must be within the range specified by the lastdrive command. If not, subst displays the following error message:

    Invalid parameter - drive1:


To create a virtual drive Z for the path B:\User\Betty\Forms, type:

subst z: b:\user\betty\forms

Now, instead of typing the full path, you can reach this directory by typing the letter of the virtual drive, followed by a colon, as follows:


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Information that the user must supply


Elements that the user must type exactly as shown

Ellipsis (...)

Parameter that can be repeated several times in a command line

Between brackets ([])

Optional items

Between braces ({}); choices separated by pipe (|). Example: {even|odd}

Set of choices from which the user must choose only one

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Code or program output

Command-line reference A-Z