>>I downloaded, installed, and have been using IrfanView. It is excellent freeware. My main complaint is that it doesn't display a whole set of thumbnails. ...
>
>
>Sorry? Simply pressing the shortcut key "T" will open a separate window, where you can select a folder. IrfanView will create thumbnails for the selected folder. Or what are you expecting?

You're right, it does. It's also in the File menu. I don't know how I missed that.