When you succeed in opening a read-protected or write-protected document by entering the correct password, protection is disabled – but only temporarily. If you close this document, the protection will be enabled again; the next time you open it, the password prompt will appear again.
To permanently remove the protection on a document, proceed as follows:
| 2. | Choose ribbon command File | group File management | Properties  . |
| 3. | Switch to the Protection tab. |
| 4. | Select the option No protection. |
| 6. | Save the document in order for the change to take effect. |
Document protection is now permanently disabled.
The next time someone opens the document, no password prompt will appear. All users can now open and save it.