If you used Insert File to insert the file, the "store a reference" check box was selected when you did the insert and you do NOT specify interactive content optimization, you can double click the container field and the inserted file will be opened with your OS specified "default application" for that file type.
An interactive format is useful for playing back audio files and reading a PDF while keeping it in the container field. I know of no reasons to use that option for MS Word documents.
Another method for opening the file that works regardless of all insertion methods, storate options and data formatting is to use export field contents to export a copy of the file and open it. You can export to the temporary folder to avoid cluttering the compute with file copies created by this export.
Thanks, Phil, that does it -- I'd specified "Interactive content optimization," and as soon as I took that off things worked as I'd hoped.