MS-DOS and Windows command line subst command

Updated: 11/13/2018 by Computer Hope
subst command

The subst command lets you substitute a virtual drive letter for another drive letter on your computer.


Subst is an external command that is available for the following Microsoft operating systems as subst.exe.

Subst syntax

Associates a path with a drive letter.

SUBST [drive1: [drive2:]path]
SUBST drive1: /D
drive1: Specifies a virtual drive you want to assign a path.
[drive2:]path Specifies a physical drive and path you want to assign to a virtual drive.
/D Deletes a substituted (virtual) drive.

Type SUBST with no parameters to display a list of current virtual drives.

Subst examples

subst a: .

Sets the current directory and subdirectories as the A: drive. So, if you were to type A: after executing this command, you would see everything in the directory from which the command was run.

If you reboot the computer, any subst command is cleared unless it was placed into autoexec.bat or another location that's executed upon starting the computer.


You cannot subst network drives and after a drive is created, you cannot give the new drive a new label.