Microsoft OneNote 2010 has password protection which is designed to help keep your notes safe from others. Whether you keep your notes for school, work, or personal record, password protection prevents sensitive information from being shown.
i. Apply a password to a section
1. Right-click the tab of the section that you want to protect with a password and the click [Password protect this section].
2. In the [Password Protection] task pane, click [Set Password].
3. In the [Password Protection] dialog box, type the password you want in the [Enter password] box. Confirm the password by typing it in the Confirm password box, and then click OK.
Note*** When you work in a password protected section, it remains unlocked for a period of time that you can specify.
ii. Change the password for a section
1. Right click the tab of the section whose password you want to change, and then click [Password Protect this Section] on the shortcut menu.
2. In the [Password Protection] task pane, click [Change Password].
3. In the [Change Password] dialog box, type the current password in the Old Password box, type a new password and confirm password by retyping and then click [OK].
iii. Lock all password-protected sections at once
1. Right click the tab of any section which is password-protected and then click [Password Protect this Section].
2. In the Password Protection task pane, click [Lock All]. (Or you can press [Ctrl + ALT + L])
iv. Set password protection options
1. Go to [File] menu, click [Options].
2. From the [OneNote Options] dialog box, click [Advanced].
3. Scroll down to [Passwords] and select your options then click [OK].