Please follow the below steps to find and remove duplicates from your EndNote library (copied word for word from EndNote Support Site)
- With the Library window open, click on the All References group to show all references.
- From the Library menu, choose Find Duplicates.
EndNote will display a Find Duplicates dialog, where you can compare duplicates and decide which version to keep and which to delete.
- For each set of duplicates, you have the option to:
- Click Keep This Record to save that particular reference and throw the other one in the Trash.
- Click Skip to leave both references in the library, intact. They will appear in a temporary Duplicate References group, so you can review them later.
- Click Cancel to automatically instruct EndNote to select the most recently-entered version(s) of each duplicate reference as the one(s) to be removed. If you move the selected references to the trash, they will be removed from the library, removing all duplicate copies EndNote found. All duplicates (including the original copy of the reference which will not be selected when the group window is created) will appear in a temporary Duplicate References group if you wish to review them. Do NOT simply move all references in the Duplicate References group to the trash unless you want to remove all copies of all references duplicated, including the original.