If you have an issue where a connected drive is not allowing you to assign a drive letter in computer management like so:

Please try this:

1. Open a command prompt.

2. Type in diskpart.

3. Type list disk to see a list of disks.

4. Type select disk #  (where # is the disk you want).

5. Type list volume to see partitions.

6. Type select volume #  (where # is the volume you want).

7. Type assign letter=x  (where x is the drive letter).