Opening a new new lister shows multiple other listers with the same path in the taskbar preview
Which method are you using to open the new lister?
Are the other windows just ones that existed before which hadn't been closed? Old windows will be remembered between restarts by default, and will accumulate if you keep opening new ones and never close the old ones (although you can turn that off).
Use the Close All Listers option in that menu, just above the bold option.
I did that but multiple of the same folder keep returning
When do they return?
Which action do you perform that makes them open?
clicked on the desktop. They don't open they are just shown in the taskbar rolover
Double-clicked the desktop background?
Or double-clicked a folder on the desktop?
(Or something else? Single-clicking the desktop would not normally open Opus at all, but might with certain 3rd party tools modifying the desktop.)
Then the windows are open, but may be minimised or off-screen, so you don't see them unless you activate them.
The desktop background
What is Preferences / Launching Opus / From the Desktop configured to do?
And which options are selected under Preferences / Launching Opus / Startup?
If you close all the windows, then open your "This PC" layout, does it open lots of windows?
If so, that's where they are coming from, and the layout must have been saved that way. You can re-save over it with a single window to fix it.