Welcome, Nelson!
I'd recommend you to try connecting the external HDD to a different computer and see how it will get recognized there. Another thing you should try is uninstalling and reinstalling the drive as a device from Device Manager. (
https://technet.microsoft.com/en-us/library/cc725782.aspx )
While at it, you should also try re-installing the USB hub controller drivers using your laptop manufacturer's website.
I'd also suggest you to go to Disk Management and see how the external HDD is listed there and go to the HDD manufacturer's website to find a diagnostic tool that will help you determine the health and SMART status. In case you cannot find such a utility, you should refer to this thread for some good third-party suggestions:
http://www.tomshardware.co.uk/forum/282651-32-best-diagnostic-testing-utility
Keep me posted.
SuperSoph_WD