D-Link DSM-600 Quick Install Manual page 14

Once you click Connect, your mapped drive will be available. Double-click
on the My Computer icon on your desktop.
Double-click the mapped drive
to access the drive.
You can assign a drive letter (e.g. E:)
to a specific folder on your internal/
USB drive(s) that is connected to your
DSM-600.
D-Link DSM-600 Quick Install Guide 1