As long as you just do this one thing

If you use OneNote for your important notes, you may want to consider what happens to your notebooks when you delete them. Is a notebook gone for good once it’s gone?

The answer is complicated, but if you delete a OneNote notebook, there are a few different ways you can recover it, depending on how you used the service. Follow the steps below to recover a deleted notebook in OneNote.

Let’s say you accidentally deleted the notes from one of your notebooks and you want to get them back. If you need to recover them, the easiest way to do so in OneNote is to use the built-in trash function. This keeps a copy of your deleted notes safely, but outside of your notebook, for up to 60 days.