Here what I would suggest to try and give it a drive letter.
Open an elevated command
window and enter the commands listed below hitting the enter key after each command.
Since it seems from the snips that you will be able to tell which drive is which by looking at the partition listings.
select disk 1
if it lists a single partition you know you have the correcd drive.
select partition 1
That should assign it a drive letter if it is able, be sure to keep us informed.