If you no longer need a notebook, you can delete if from your computer or from a shared location.
Important: After you delete a notebook, you may not be able to recover it. Always back up important notes before you delete them.
Delete a OneNote notebook from your computer
If you know you’re never going to need a notebook again, you can delete it from your computer.
In File Explorer, navigate to your Documents (or My Documents) folder, and then double-click OneNote Notebooks.
In the OneNote Notebooks folder, right-click the name of the notebook you want to delete, and then click Delete.
To remove the deleted files from your computer, right-click the Recycle Bin on your computer’s desktop, and then click Empty Recycle Bin.
Delete a OneNote notebook from a shared location
Before deleting a notebook that you’ve shared with others, let everyone who has permission to view or edit the notebook know that you’re planning to remove the notebook, or they may lose important work.
In the Notebooks list in OneNote, right-click the name of the shared notebook that you want to delete, and then click Close this Notebook. (Shared notebooks have a synchronization icon shown next to their name.)
Go to your shared notebook (for example, use File Explorer if the shared notebook is stored on a network file share, or use Internet Explorer to view your notebook folders on OneDrive).
Right-click the folder, and then click Delete.