Paul Korm wrote:

The setting is there, but somewhat buried. If you click a notebook in
the sidebar, then in the next panel to the right you click the three
dots at the top (a tooltip says "More Actions") then in that menu you
can set the selected notebook as the default notebook.

Hugh wrote:
Hmm, Version 10 apparently lacks Preferences for the time being. Does
>that mean that you can't choose a default Notebook? If so, that's a
>disincentive to upgrade just yet.

Many thanks, Paul.