I have Windows 10 and Ubuntu 15.04 set up in dual boot. They are both running off of a 120GB SSD. I have mounted a 1TB Western Digital drive on Linux perfectly fine, however the same drive does not show up in Windows. It is not registered in disk management or the device manager.
EDIT:
Here is Windows: You can see my ssd and my other 2TB drive.
http://i.imgur.com/RtXoFh2.png
in Linux:
Here is my 1TB HDD, working perfectly fine in linux, mounted as an NTFS partition(not available in Windows)
http://i.imgur.com/UWIxjKr.png
EDIT 2:
I unplugged/ replugged it, reinstalled both OSs(for unrelated reasons), and it works now. Thanks to all that helped.