For several years I have used onenote 2010. A few weeks ago I downloaded onenote 2016, thinking that my 2010 notebooks would be brought over and put into onenote 2016. But not so. Can anyone tell me how to accomplish this, I would rather not use Onedrive if possible. I did notice that my onenote 2010 may not be connected to my MS account.
Ideally OneDrive should be used but if your 2010 notebooks are on the same PC as OneNote 2016 then select File and then Open and navigate to where the notebooks are stored. Select them & they should appear in 2016.