Delete duplicates from a table with all the columns duplicated
If you can, add an UNIQUE INDEX (or PRIMARY KEY) for [ID].

And you could change:

DELETE FROM [dbo].[monthly_prd04_ftp_list]
GO


by

TRUNCATE TABLE [dbo].[monthly_prd04_ftp_list]
GO


It's faster and it will reseed the identity column to 1 (or it initial value.)

If you don't want to use a temporary table, and there isn't FOREIGN KEYS pointing to this table, you could rename it and insert the DISTINCT values to the final table directly. Then you could DROP the old table.