Show open Excel files as taskbar pop-up list instead of thumbnails

Hello,

Where is the setting to always show currently-running/open Excel files in a pop-up list from the taskbar rather than as a row of thumbnail images?

When I left-click the Excel icon on my taskbar, it displays a row of thumbnails across the bottom of the screen. I can see the advantage in that since you can sometimes find a particular sheet more quickly that way. However, most of my Excel files look similar and the disadvantage to the thumbnail view is that part of the filename is commonly obscured. For me, this more than negates any advantage gained by the thumbnails. A pop-up list replaces the thumbnails once there are too many to display across the width of the screen, but "too many" is around 16-20 which is many more than I typically have open.

I am running Excel 2010 and at some point in the past, it was configured to never show thumbnails but always show a pop-up list, even if only a handful of files were open. Can someone help me locate that setting?

By the way, I am not referring to the "Recents" pop-up list which appears when you right-click the taskbar icon.

Also, it just dawned on me that this is probably an Office setting (or even a Windows setting) rather than specifically Excel and it may require going into the Registry. I think that's what it's called (the place you don't want to go unless you really know what you're doing). Btw, OS is Windows 10.

Thanks