Summary
The desktop versions of Microsoft Office applications provide the ability to securely encrypt Word, Excel, and other document files.
(Note: Word Online and Excel Online cannot save or open encrypted files.)
Full step-by-step instructions are attached.
Body
Word Document Encryption Instructions (Quick Summary)
1) Open the File menu to access Office’s document security and protection options.
2) Click on the Protect Document button to open Office’s menu of document security and protection options.
3) Select the Encrypt with Password command from the list of security and protection options.
4) Enter your password into the Password text box and click on the OK button.
5) Reenter your document’s password and click the OK button.
6) Check for the "A password is required to open this document" message to confirm successful encryption.
7) Click on the Save button to save your document in the encrypted format.