Xbox is saying my external hard drive is write protected even though it isn't

I've been trying to get my 1TB External Hard Drive to work with my 360. Problem is, I keep getting told it has write protection on it even though I have gone through it many times and disabled write protection. every time, it says it is on even though it
isn't. It is USB 3.0 and 2.0, and has been reformatted to NTFS and exFAT, both to the same results. I have already trawled through google and MS's support pages and not found anything like the problem I'm getting. Help would be appreciated.

:)

 

External Hard Drive on the Xbox One

Is there a way to save my save data on my internal hard drive and then save my game data on the external? I want to make sure my game saves are protected if my external hard drive crashes.

 

USB storage write-protected issue

So I was about to play on my xbox 360 :3, but when the logscreen appeared there where no accounts. I checked my external hard drive (not the xbox one, a hitachi HXSLMA), but when I tried to open it, a message appeared saying that it was "write-protected".
Could you tell me how to solve this? P.S: I'm using a Mac (running OSX 10.7.5) so if you find any useful app for this let me now!

 

What brand of hard drive is it? Perhaps the drive is not supported. Also, even if you were able to get it working you would only be able to use 32GB of space from the drive.