It seems you have some setup files mounted to your machine or setup disk inserted.
Please go to your Desktop and Unmount or Eject them.
Note : You will be able to find them using the names which you see in Lightroom.
Hope this helps.
This happened to me when I first installed Lightroom/cc and Photoshop/cc. A restart of the computer and Lightroom unmounted the DRIVES and no problem since then.