Restoring the OneNote Guide

If you didn't delete the OneNote Guide notebook folder then you can do this:

1. Open OneNote
2. File-->Open-->Notebook
3. Go to Documents\OneNote Notebooks
4. Find the OneNote Guide folder and click on it
5. Click Open
6. Success!

If you deleted the OneNote Guide notebook folder then please do this:

1. Open OneNote
2. File-->Open-->Section
3. Go to %programfiles%\Microsoft Office\OFFICE12\LCID\
4. The LCID is the folder for your language & locale; for EN-US this is 1033
5. Double click on ONGuide.onepkg
6. Unpack the notebook by going through the wizard
7. Success!

Reference: Restoring the OneNote Guide