Microsoft DOS subst command
Allows you to substitute a folder on your computer for another drive letter.
The subst.exe command is an external command that is available in the below Microsoft operating systems.
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 a: .
If you reboot the computer any subst command is cleared unless command placed into the autoexec.bat or other location that is executed upon starting the computer.
Tip: You cannot subst network drives and after a drive has been created you cannot give the new drive a new label.