Oversized Photo Display

[Padeen Coleman]

Starting yesterday every photo I open displays as an expanded view, so I see only a small portion of the photo. Also, the previous and next buttons no longer advance to the next or previous photo, but just move the current oversized photo around. I assumed somehow the "fit to window" in settings became unchecked, but on confirming that it IS checked, I haven't solved my problem. I updated Irfanview before looking for help, but the updated program is doing the same thing.
Question: How do I get all photos to open in full view shrunk to fit my screen, and do it for all photos (all 134,283 pictures)?
Thanks in advance.
Padeen

[Bhikkhu Pesala]

Fit to Window is not in settings; it is on View menu, Display options (Shift+W shortcut).

The Next/Previous File buttons do what they should do here, whatever the zoom level is. See Settings, Browsing/Editing, and Settings, Extensions to folder browsing options.