Chad Callihan shows one of the best ways to remove duplicate records from a table:
Have you ever needed to delete duplicate records from a table? If there is only one duplicate in a table then simply running something like DELETE FROM Table WHERE ID = @DupRecord will do the trick. What happens when the problem is found after multiple records are duplicated? Will tracking them all down be more time consuming? Here are a few different options for quickly clearing out duplicate records.
There’s the best way, and then there are the other ways.