Which version of Office are you using? If Office 2007, try this:
1.Click Start ->Run (windows key + R key) and type appwiz.cpl-> click ok.
2.Click on OneNote 2007 and click on Uninstall or remove.
3.If OneNote 2007 is a part of Office 2007, click on Office 2007-> Change.
4.Click on continue or next for Add/Remove features.
5.Click on the little arrow attached to Microsoft OneNote and select Not available-> continue.