Just as you can lock people out of your computer by using a password, you can "lock" a document. You can password-protect your document if you don't want other people to see it, or if you don't want others to edit it.
Password protection for documents is available in various Office programs. In Word, Excel, and PowerPoint the method is exactly the same.
On the Tools menu, choose the Options command, then click the Security tab. Here you can select from several options, including file encryption and file sharing, to help protect your document.
The Password to open option is designed to help safeguard your documents. The Password to modify option is not a security feature. It is intended to help you prevent accidental changes to your documents.
Information about additional features on the Security tab, such as Privacy options, is included in the Quick Reference Card at the end of the course.
Refer to each program's security Help topics for more information on how to secure your documents in other Office programs.