I have the same problem with three WD Mypassport USB HD. I unistall the driver and re-installed again, only two of them connected.
I connect the "failed" drive into my Samsung TV and it work. I can see all my files and pictures and videos. But nothing in any computer. I used the same cable and connector. To double check, I connected the other HD into my TV Samsung and all work.
Here is the question: Why this "failed hard disk" cannot connect to my Pc but yes, it connects to my TV Samsung? Is it a driver problem? For sure.
Can WD be responsible on this providing me the reigth driver? May the latest driver don't work in more than 5 years olde MyPassport disks?