How do I remove the groupings (e.g., 0-9, A-H, Unspecified) in file folders so that all the files (irrespective of type, date, etc) are simply listed alphabetically? I've tried many 'Sort by' options but none have removed the groupings. Help!
This behavior isn't available in the file handling dialogs (Open, Save As, etc.) in Office, so I assume you're asking about the Windows File Explorer.
On the View ribbon of File Explorer, in the Current View group, click the Group By button and choose None. The separators appear when the Group By is set to Name.
Note that the Group By setting is independent of the Sort By setting that includes the same list of items. Sort By controls the order in which files are listed.