My Book 3 TB external hard drive corrupted

I have a Western Digial My Book (3 TB) external hard drive.  I was accessing it and my computer locked up for some reason, the only option I thought I had was to physically turn it off with the power button.  When I turned it back on I got an error (something like the drive letter J://$mbr or something like that, maybe $msf, I am not entirely sure and I am not sure what the error message said).  I went to access my hard drive again and it was not in visible in the Device Manager.  The computer was recognizing the USB cable from the external hard drive.  I tried the hard drive on another computer and the same thing occured.  I downloaded the Data lifeguard diagnostics program from and it found the drive, however says the size is 0 mb.  I’m thinking it’s the MBR that is corrupted (again, I’m not entirely sure what the actual error message was). 

Any assistance would be greatly appreciated.  All of my PhD data was on that drive, I’m desperate to get it back!!

If the drive shows in Dusk Management something like this might help. A 3 T drive will be GTP instead of MRB. There are other data recovery programs that are try and buy. If the data is really important and you are thinking about professional recovery it’s best to do nothing.