If you have old .ONE, .ONEX, or .ONEPKG files that you can no longer open, don't delete them immediately. The issue could be related to an outdated application, file compatibility, or the fact that OneNote is no longer installed on your computer. First, make a backup of the original files so you have a safe copy to work with.
If opening the files directly isn't practical, converting them into a more accessible format can be a useful alternative. RecoveryTools OneNote Migration Tool supports these OneNote file types and can convert them into formats such as PDF, DOCX, HTML, JPG, and PNG. It also supports batch processing and works offline, allowing you to handle multiple old notebooks locally. This can make archived OneNote content easier to read, share, print, or preserve for future access.
