When I goto place a PDF file in indesign and if I have the preview window turned on in the dialogue, the preview does not appear to the right in the dialogue box, it appears in the top left of my monitor.
This only happens in indesign
It only happens with PDFs, jpgs etc preview in the dialogue box as it should.
Try resetting your preferences: The easiest way to reset everything is to delete the InDesign preferences: as soon as InDesign starts to boot hold down Shift, Alt, Ctrl (and Apple/Cmd if working on a Macintosh). A dialog will appear asking to delete the InDesign Preferences, select 'Yes' on this dialog. Further info and instructions here if needed: https://helpx.adobe.com/in/indesign/kb/indesign-preferences-support-file-locations.html