I would like the TeXstudio previewer to run "windowed", rather than "embedded". The "Configure/Build" screen claims to give me my choice, and changing from "Internal PDF Viewer (Embedded)" to "Internal PDF Viewer (Windowed)" works properly for the rest of the current session of TeXstudio. But, if I exit TeXstudio and restart it, then the previewer mode has mysteriously changed back to "embedded".
I am running TeXstudio version 2.10.2 under Windows 10. This issue doesn't seem to be a problem, say, with write permission on the ".ini" file, since changes to other settings are correctly remembered across sessions.