Well, the HDD is simply a SATA drive, formatted as ext4, with a number of partitions.
So you will need an ext4 utility for Windows. You could try the free trial version of this:
You may not need a USB enclosure: you could simply open up a modern desktop PC, and connect it to a spare SATA socket on the motherboard. But! DO NOT LET WINDOWS FORMAT IT! It will not be recognised. Hopefully, if you have an ext4 utility, it may detect the ext4 drive.
You might also search the forums for ‘recovery’; there have been discussions of this sort before.
http://wdstagingsplit.staged-by-discourse.com/search?q=Recovery%20category%3A105
I’m assuming you have tried the usual 40-second reset and other debugging steps, and disassembly is the final resort.
