Ringtones won't appear in my Library or Tones folder?

So I got an iPhone 5 for my birthday the other day as they were going cheap with the iPhone 5s out, and I've been really wanting to make my own ringtone.

I have one already and downloaded, and I've changed it to the m4r extension so that it comes up in Windows Explorer as 'ringtone' but when I try and put it into iTunes, it won't appear. I have the Tones tab open, and it won't appear there, either.

I reaaaally want to know how to fix this, so I don't have to have the boring old tunes. I have the latest iTunes, could anybody help? I've tried dragging, copying, pasting, addingthe file to the library, nothing seems to work.