Plug the phone into your computer USB. A dialog box will come up and tap "mount as a disk drive" Unplug the phone and then replug in the phone. You should be able to go to "my computer" on your computer and see your card. After you are done I would suggest using your safely remove hardware function before disconnecting your phone since you will be actively using the SD card.
On edit: I missed you were asking about the internal drive, sorry my bad.