Many companies and users are still on Office 2010 with no immediate  plans to go to Office 2013. This means they are missing out on the improvements made to OneNote 2013. Until recently the free download version of OneNote 2013 was missing several key features. This has been resolved and we are not suggesting users of Office 2010 migrate to OneNote 2013 which can be donwloaded below. Some of the unlocked features include:

• Password protected sections—Add a password to protect sensitive information.
• Page history—Easily see or go back to prior versions of a page.
• Audio and video recording—Take notes while recording, and easily jump to the relevant section later.
• Audio search—Search for a word in a voice or video recording.
• Embedded files—Insert Office documents or other files directly in your notebook.

Source: OneNote Download