Greetings Tina,
If you navigate back to Word’s Templates and Add-ins window, are you able to highlight the unchecked “EndNote CWYW Word 2016” add-in listed here and remove it by pressing the minus symbol button found on the same window? If you’re unable to remove this entry by pressing the minus button, or if the add-in re-appears on this window after removing it and restarting Word, I’d suggest resetting preference files associated with your Word installation. To do so, please visit the following knowledgebase article:
The last section in this article is entitled “Tools are Missing, but everything appears correctly configured:”, and outlines the steps associated within resetting Word’s preferences.
Please let me know if this helps.