How to save documents as .doc
Word
365
By default, Word saves all documents in the newest format (*.docx), but you can change the default format to
.doc or anything else.
To do this, follow the next steps:
1. On the File tab, click the Options button:
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2. In the Word Options dialog box, on the Save tab, choose the format you prefer in the list Save files in this format:
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3. Click OK.
See also this tip in French: Comment enregistrer des documents au format .doc.