Go the the website of WD... ...and look for your HD. Get its model number and put it in the box on the right hand side of the page. Once you have found your drive you can download a tool to check your HD is working ok or not and or wether or not it needs a driver update. If you still aren't happy email or phone them. You'll find the links for that also on the right hand side of the page.
Amazon Fire HD 8 review: A brilliant combination of function and value – with one massive caveat