This example shows you how to make your workbook read-only. Users can still save changes by creating a new copy of the workbook. For a better protection, protect the sheet with a password.
1. Open a workbook.
2. On the File tab, click Save As.
3. Click Browse.
4. Click on the Tools button and click General Options.
5. In the Password to modify box, enter a password and click OK.
Note: If you only want to recommend users to open the Excel file as read-only, without protecting it, don't enter a password and check Read-only recommended.
6. Reenter the password and click on OK.
Note: this feature does not encrypt your Excel file.
7. Enter a file name and click Save.
Your workbook is read-only now.