Helpful DOS commands

wmic logicaldisk get deviceid, volumename, description (show mounted drives)

sdelete -p 2 C: (two passes to securely delete C:)

sdelete [-p passes] [-r] [-s] [-q] [-f] <file or directory […]>
sdelete [-p passes] [-q] [-z|-c] <drive letter […]>
sdelete [-p passes] [-q] [-z|-c] <physical disk number […]
Parameter Description
-c Clean free space.
-f Force arguments containing only letters to be treated as a file/directory rather than a disk.
Not required if the argument contains other characters (path separators or file extensions for example).
-p Specifies number of overwrite passes (default is 1).
-q Quiet mode.
-r Remove Read-Only attribute.
-s Recurse subdirectories.
-z Zero free space (good for virtual disk optimization).
-nobanner Do not display the startup banner and copyright message.