External dvd drive shows up among the other drives, but not in Disk Management (trying to change drive letter).

[Fynriel]

It's ready for use and like I said it's visible in "My Computer", but it's not listed under Disk Management. So I'm unable to assign a different letter to the drive.
What am I missing?

 

[bailojustin]

Go to your computer screen where it shows the normal Hard drive, then click organize, folder and search options, then view, and click show hidden files folders and drives.