Why is my dvd drive not showing up?

I’m using windows 7 and when I open windows explorer, my dvd drive does not show up. If I insert a disc in the drive it does show up. How can I have it show up all the time? I don’t want that drive letter being used for thumb drives I insert.

I have been to the section – Tools – Folder Options – View and have unchecked the box that says “Hide empty drives in the Computer folder”.