What is your drive's manufacturer/model? It could be a WD with Relo problem, but it can also be a hundered other things.
1. If you care about your data:
1a. If you care about your data a lot, do not plug in the drive anymore and send it to a reputable DR lab. If you specify your area, we can recommend someone.
1b. If you don't care that much about your data, you need to take it out of the external box and see what you're facing with. It could be something very simple, otherwise it will be necessary to go to 1a.
2. If you don't care about your data, bin the drive and move on.
Oh, and you need legit windows.