How to open database in new/second window?

[Spliff]

(i.e. the same database (?) or another database, the latter is what I search for, the former is probably not possible anyway, in order to avoid problems)

google search ("Ultra Recall" "new window"; ditto for "second window"), forum search and help search have not been successful for me; that UR calls panes "windows" doesn't help either for this search.

Options - Misc. - Allow opening multiple instances (I suppose this is the basic condition for this, so I toggled this ON).

File - Open > in this (MS Windows) dialogue, there is NO option "in new window", so it opens in a new tab

View - Other Windows > just other PANES here

Window - Next/Prev Database only here, no "New Window"

Rightclick on Database tab > NO "Open in new window" here

I know it is possible since I had two UR databases in two windows on the very first day of my 6.0 trial, but I don't get to it anymore. Also searched Options and Quick Options.