when I keep typing in one textbox, my OneNote 2013 would change the typeface. Is there anyway to fix the typeface? I tried to set up a default font but it does not work.

Hi,

Did you install any add-ins in OneNote? Please go to File > Options > Add-ins and disable all add-ins to check the result.

In addition, please open your OneNote and go to File > Options > Language, in the Choose Editing Languages, Remove everything except the language you are using.

Please let me know the result. Hope this helps.

Best Regards,

Steve Fan
TechNet Community Support