Backups continue to go into OneNote

To stop OneNote from creating automatic backups in the local data/Backup folder, change or disable the backup settings in the desktop OneNote app (OneNote for Microsoft 365 / 2016 / 2021 / 2024):

1. Open OneNote on Windows (desktop version, not OneNote for the web).
2. Select File > Options.
3. In the OneNote Options dialog, select Save & Backup.
4. Under Save:
   • To reduce backup impact instead of fully disabling:
     • Set Number of backup copies to keep to a lower value.
     • Optionally change Backup Folder to another drive or location using Modify.
   • To stop manual/automatic backups from running:
     • Turn off any scheduled backups by adjusting the backup frequency options so that automatic backups are not created (and avoid using Back Up All Notebooks Now).
5. Select OK to save changes.

To clean up existing backup files already stored under your data folder:

1. Open File Explorer.
2. In the address bar, type %localappdata% and press Enter.
3. Open Microsoft > OneNote > 16.0 > Backup (version folder may differ, but the structure is the same as described).
4. Delete the backup files or folders that are no longer needed.

If using OneNote for the web only, note that it does not create or manage local automatic backups; those are controlled only by the Windows desktop OneNote app.

References:

• Back up notes
• Fix issues when you can't sync OneNote
• Backup and restore notes in OneNote for the web