Onenote not connecting to correct account.

[Windows Central Question]

I have a new PC with windows 10 + old laptop (updated to windows 10 originally 7). I have office 365 and one drive. If I open the onedrive app it asks for an MS sign in. When I put in my email and password I get 'you're synching a different account'. So I right click the app icon, go to settings account but see a message 'you don't have an account connected....'. So I try to add an account and get the message 'Your're already sycing a personal Onedrive. Unlink account and add a new one'. Unfortunately there is no where to unlink an account and the dialo box has only 3 tabs not like the new one on my PC - it appears to be a left over from Skydrive. How do I get a full dialog box and update to the correct account then synch. my files. Note I have another (new) laptop which synchs. fine.