How to Protect Your Word 2007 Document
In Word 2007, you can protect your documents from being modified, or changed, by others. The easiest way to protect your document is to use the Protect Document command button.
Click the Review on the Ribbon.
The Review tab is the sixth tab from the left, located between the Mailings and View tabs.
In the Protect group, click the Protect Document button.
The Protect group is the last group on the far right of the Ribbon.
Choose an option from the Protect Document drop-down list.
Your protection choices include limiting formatting styles and restricting certain types of document editing.
Try to avoid locking your document unless you must. There is an advantage to locking your document: You are the only one who can open it. However, when (not if, but when) you lose the password or forget how to open the locked document, you’re screwed. No one can help you. Not Microsoft. No one. That’s why it’s better not to mess with this option unless you absolutely must.