For devices with multiple hard drives sometimes only one hard disk is displayed. The reason for this is that the further drives need to be initialized.
This can be carried out as follows: Click the Start button and enter Computer Management > storage> disk management. A warning box may appear telliing you that a drive has yet to be initialized. Confirm this message by clicking 'ok'. Choose the hard drive to be initialized then right click and select 'initialize'. The drive will then automatically initalize. After this you can partition the disk to your wishes and adjust the driver letter if needed.