A full amendment of the SQL to perform this task has been made. Following are the steps to install this powerful SQL!
Copy the following SQL to a text editor so you can see better (WordPad would be great as you can maintain color of the tags). Your going to edit the SQL, and its important you maintain spacing and brackets where you see them.One error here and it won't work!
DELETE [DF] FROM [TN] WHERE [ID] Not In (SELECT Max([ID]) FROM [TN] GROUP BY [DF]);
In the SQL you'll see three tags:
DF is YourDuplicateFieldName
ID is YourIDFieldName (usually the primarykey)
TN is YourTableName
Parse thru the SQL and replace the tags with the proper names.
When your sure your done, open a new query in design view (do not select any tables) and copy/paste the SQL into SQL View (be sure to paste over the Select; that already there).
Switch to DataSheet View to test its working and view the records that will be deleted. From here your ready to fly!