You're doing all the right things ... the problem is with the disks, not with anything you're doing. Unknown and not initialised means that the disks are unreadable for any number of reasons. The disk metadata could be damaged or the partitions could be messed up. Or the file system could be a format that Windows 10 can't read.
This is often fixable but you'll need 'partition manager' software, which you install on Windows. Then attach the hard drives (via USB) and open the software, which will analyze the disks, tell you what's wrong and how to fix it (if indeed it's fixable.)
I have not worked with this kind of software in several years, so I'm not the best person to advise you. I used Paragon Partition Manager, but there are lots of other choices. You can find them by searching the web for: windows 10 partition manager software
Partition manager software is very powerful and also very complicated. It's definitely not a matter of 'follow these three easy steps ...' You'll have a learning curve and you'll have to be extremely careful. There are no do-overs with this type of software. But - you can do it.