Method 1. LOCK buttonBefore click the button, we should make sure the button apparent on the Word Quick Access Toolbar. Launch Word 2010, navigate to toolbar and from small drop down button, select More Commands. Just like the followed figure.
Then you will get a Word Options dialog box. Go Choose commands from>All Commands, and you can see all cammands. Next, scroll down the list, find eht lock command and click on it. Select the buuton Add>>. Now you can see the lock button is on Quick Access toolbar pane. Just hit OK.
After these operations, the Lock button in the Quick Access toolbar.
Click the button, and no one can write, edit, or modify. And click it again, the document is unlocked.
Method 2. EncryptLaunch Word document which you want to protect with the password. Go menu>Prepare>Encrypt Document. Just like the figure below.
Now a Encrypt Document box appearants. What we should do is just enter the password twice.
So far, you have lock your document with your own password. Another thing you should konw is that cancel the password is in the same procedure. The only difference is that you should make sure the password box is blank, and then save the file.
These two ways are all useful. Which one you will choose just depend on your conditions. Each one will be a nice helpful tool.