OneNote 2010 is undoubtedly one of the best note taking application and it comes with tons of features for customization. It comes included in Office 2010 suite. If you have created lots of notebooks with OneNote 2010, it is always good that you keep a back up of all the data. OneNote 2010 has an in build feature of taking a backup of all your created notebooks. This backup can also be taken automatically.
To take a backup of notebooks in OneNote, click on the file tab and select options.
In the options window, select the Save & Backup tab. Here you can see the default location where the backups are done, you can click on it and modify it. There is also option to automatically do the back up at interval set by you.
You can also specify how many back up copies to keep at a time. Once done, click on the Backup all Notebooks Now button. If you have set auto back ups, it will be automatically saved at regular intervals.