Enter the command 'diskpart' (without the quotes) and press enter followed a cmd shown below. 'List Disk' shows you the basics.
You can list the available objects and determine an object's number or drive letter by using the list disk, list volume, and list partitioncommands. The list disk and list volume commands display all disks and volumes on the computer. However, the list partition command displays only partitions on the disk that have focus. When you use the list commands, an asterisk (*) appears next to the object with focus. You select an object by its number or drive letter, such as disk 0, partition 1, volume 3, or volume C.