Q. How do I lock a document so that it cannot be changed/edited?

To Lock a Word document and keep someone from modifying it, set a password;

• Click the Microsoft Office Button ,
• Cclick Save As, and on the bottom of the Save As dialog, click Tools.
• On the Tools menu, click General Options
• Under File sharing options for this document, in the Password to modify box, type a password

Just remember the password that you set for your document.