Yeah it's there you need to right-click on it (on the black bar for Disk 2) and tell it to Allocate, or to "Setup a Simple Volume" something like that, if you can post another screenshot of a right click I can help better.
Pro Tip:
Use the "Print Screen" button and copy/paste that into Paint and you can either crop it in there or use the snip tool to take a picture of a picture.
Is there data on it? Because if there is then it isn't being read correctly so you will need to unplug/replug it.
Question then. I have files I want on the HD, is 'Allocating' it going to 'format' it?