For a while, I thought I would have to wait for Windows 10 to adopt special drivers that should make my Western Digital My Book external hard drive compatible with this Windows 10 PC...except that doesn't make much sense. Turns out it was simply a matter of what version of USB port I had it plugged into. It needs the old USB 2.0 port instead of a USB 3.0 port.
This should be like a sticky post for anyone having trouble getting, specifically, a western digital external hard drive to work right with their Windows 10 PC. I can't say that my solution would work for everyone, but considering they work just fine with old PCs equipped with Windows 7, it makes perfect sense since they use mostly USB 2.0 ports. I should probably put some arbitrary text below so people looking up a solution can find this post easily (as many did with my Skyrim RaceMenu presets journal).
Glad to help anyone having this same issue! :D
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