I have an external hard drive that backs up my 2 computer drives at 2 different times during the day. I have been getting some errors recently when trying to back up. The errors stopped for about 2 days but then started up again last night. The error I got I/O Device Error.

It then says M: (drive of my hard drive) failed, etc etc. This drive is a western digital drive & is probably 3+ years old. Could be even older, as I cannot remember, but it is an original MyBook. I even ran some diagnostics the other day from western digital but everything came up with passing the drive.

So my main question, is is this my external hard drive failing? Or is it my computer failing? If its the drive, no problem I can get a new one. If it is the computer than that would worry me alot more. Any responses are appreciate, thank you!