OneNote automatically stores backups of your notes on the same hard disk drive as your original notebook files. This helps to protect your notes from being accidentally changed, corrupted, or deleted while you work. It also makes restoration of recent notes quick and easy.
However, to protect your important notes from a serious problem, such as a hard disk failure, consider changing the default location of your OneNote Backup folder. Suitable backup locations for your important notes include a folder on a secondary or external hard disk drive, a removable storage device such as a USB drive, or a private folder on your network.
Depending on your computer's operating system, backups of your notebook files are stored in one of the following default locations:
On Windows 10, the Backup folder for your notebooks is located at C:\Users\user name\AppData\Local\Microsoft\OneNote\version\Backup.
On Windows Vista, the Backup folder for your notebooks is located at C:\Users\user name\AppData\Microsoft\OneNote\12.0\Backup.
On Microsoft Windows XP, the Backup folder for your notebooks is located at C:\Documents and Settings\user name\Local Settings\Application Data\Microsoft\OneNote\Backup.
Change the default location for backup files
Click File > Options > Save & Backup.
(If you're using OneNote 2007, choose Tools > Options > Save.)
Under Save, in the Paths list, click Backup Folder, and then click Modify.
In the Select Folder dialog box, navigate to the location of the folder where you want OneNote to store backup files, and then click Select.