Sounds like a mechanical failure, since windows detects the drive the controller may be working, but with a mechanical failure (like head crash, which WD tend to suffer from more than Seagate), this is the sort of symptom you will see.
If you haven't been backing up the data the news is not good. Data recovery is a niche market and specialists charge ridiculously high costs for recovering your data. Many change by how much data they retrieve. And they often won't turn it around quickly for you unless you pay them more.
I doubt this will work, but you could try booting of a disk like Hiren's Boot CD (or something similar). These have a collection of tools for working with hard drives. From time to time I've managed to get some data off a failing drive... But that's the keyword "Failing" they weren't completely dead. A couple of hours worth of work to try it.
Google hard disk data recovery.
I've been through this scenario myself. I bought all sorts of tools off the internet, and none of them worked. My failure was a seagate, which tend to suffer controller failures. In the end I lost 15 years of family photos. Lesson learned.
Good luck