[jamesB]

Questions:

1. In any finder window there are two hard drives. They are identical. There's only one on the desktop. In the old days, I would look for two system folders but what do I look for now? (There isn't two system folders.)

Just in case you're referring to the finder right-hand pane, just ctrl+click on the drive icon and select remove from sidebar.

jb.

 

[jamesB]

Thanks, JamesB, as stated above, they're both identical. I don't know which is the "real one". I'm afraid of what will happen if I remove the ''wrong one"..

Remove either one, they are just alias's pointing to the same drive, easy thing to put back should you want to.
You can drag-n-drop pretty much anything you want into the left pane of the
Finder.

jb.

 

[jamesB]

Here is something easy to try,
go to Finder-Preferences-Sidebar
Deselect all the Devices, then 1 by 1 reselect them.
This might clear the rogue HD icon.

jb.