Learn the syntax for the subst and sdelete commands.
Reference syntax for “subst”
PS C:\Users\Administrator.CSGLAB> subst /?
Associates a path with a drive letter.
SUBST [drive1: [drive2:]path]
SUBST drive1: /D
drive1: Specifies a virtual drive to which 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.
Reference syntax for “sdelete”
PS B:\> .\sdelete.exe /h
SDelete - Secure Delete v1.61
Copyright (C) 1999-2012 Mark Russinovich
Sysinternals - www.sysinternals.com
usage: B:\sdelete.exe [-p passes] [-s] [-q] <file or directory> ...
B:\sdelete.exe [-p passes] [-z|-c] [drive letter] ...
-a Remove Read-Only attribute
-c Clean free space
-p passes Specifies number of overwrite passes (default is 1)
-q Don't print errors (Quiet)
-s or -r Recurse subdirectories
-z Zero free space (good for virtual disk optimization)