My Passport 0740 isn't detecting/

I have a western digital My Passport 0740 hard drive. It's about 3 years old now and has been working fine until one day it just stopped. It's not recognised on My Computer but I followed some other instructions about going into Device Manager and looking to see if it is registering on there and it is. The popup says that it is working properly and I tried updating drivers but it says it is up today. I've tried a different cable and nothing.

I have about 1Tb of stuff on there so I'd really like to try and get the HD working if at all possible. Or is there a way to get the stuff off it. I'm slightly limited for computer space at the minute as I am using an Asus Transformer tablet which is running Windows 8 or 8.1. I can't remember.