Yes, you can add pics. You should be able to add on a new thread, and when replying to a thread you need to click on "Full Editor & Preview", which lets you add and upload a few images (and other files). Not sure if you need a certain number of posts first though, but I think not.

A Win 10 PC should see any partitions or empty drives the same as when you add a new drive. I have no experience of adding drive via a usb adapter, but a usb drive will usually be below your internal drives if formatted, otherwise you might need the disk manager.

No do not post a new thread (that means a new topic in most forums) to add pictures here in this topic/thread...
Just start a new comment here in the "quick reply box" (like: here are the pics) and then click the word "Full editor" below the text box, then click Attachments and then Add files and browse to the .JPG (preferred format of a picture) of less than 1Mb if possible but hi-res.
AFAIK the only limit on new members is ability to to do a PM...

🤣, I wasn't meaning for Lorne to post a new thread, sorry if it looked that way. Was just saying how it can be done.

In W10 you can right-click on the start button and select 'disk management', which will show all drives connected even if there's no letter assigned. Although I suspect that if it doesn't show a new drive after playing the mounting sound then W10 probably can't see a partition. That's the point I'd probably pull out linux and start playing around with 'dd' to see if there's any data at all.

For non-spinning disks I've seen lots of tales of cooling the disk down, or giving it a twist just as power is applied to try and give the motor a push. Haven't had much luck with those myself. I did have a Seagate U4 (ST34311A? Maybe? One with a weird rubber cover, a lot newer than your Seagate) that wouldn't spin up. I managed to get working again by swapping over its firmware eeprom from the control board of another (I assume the actual disk parameters are stored elsewhere). So non-spinning isn't always hardware. There may also be a fuse or over-voltage device on the board. So it might be possible to make that one work. Photos of the control board might help.

So. After much trials and tribulations. We managed to get into W10's Device manager. It saw the USB adapter but not the Caviar. I rummaged about and found a IDE Western Digi WD800 80Gb Marked Granpas HD. So W10 had no issues with that one. Copied of some files for conservation and went to format. NTFS OR ExFAT. I think FreeDOS wants FAT 32. I thought if I could format the driv off W10 it would be faster.......
The 386 does not see the WD800. I wonder if thats because of the size or file formate?
I'll give Disk Management in W10 a try then maybe look for some utility I can run from W10. fdisk ?

Google tells me this. And we all know never doubt Google.

"Why can't I format a 64GB SD card to FAT32?
It is usually due to that your partition is larger than 32GB. Because the default Windows format option only allows the FAT32 partition on drives that are 32GB or less. In other words, Windows built in formatting methods like Disk Management, File Explorer or DiskPart won’t allow you to format 64GB SD card to FAT32."

So perhaps I will format the drive into smaller partitions then see if one partition can be formated to FAT32.
I was googling the BIOS to try and see if there was something to be learned there. But nothing popped up.

Ok Noticed something new I had not before. In the BIOS it detected a floppy.... I didn't look close enough. I assumed since the 3.5 was plugged in an d bot the %' that it was seeing a 3.5. No it sees a 5". So looking at the IO card there is a dozen or so jumpers. Anyone have documentation on a Biostar FI33290UIO1012. I'm guessing this is the part model. As far as I have figured out so far.
As to swapping IO cards. I have others. But they are from AT cases, might be some more in the Tandy's or Commodore. Is an ISA IO card interchangeable on any of these?