I just replaced a computer for one of our users. It is running Microsoft Office Professional Pluse 2010. She says that on the old computer she was able to click the OneNote button on the menu of a calendar appointment to add notes about the meeting but on the new computer she does not see the OneNote button. I did a web search and followed the recommendations to enable "OneNote notes about Outlook items" in Outlook > File > Options > Add-ins. But OneNote was not listed in the Com Add-ins or the Disabled Add-ins lists on the new computer. I had the user Repair Office from Programs and Features but still no joy.