Ejemplo de SQL FIDDLE
1) Use CTE para obtener un registro de valor de código de envío máximo basado en ARDivisionNo, CustomerNofor cada Cliente
WITH cte AS (
SELECT*,
row_number() OVER(PARTITION BY ARDivisionNo, CustomerNo ORDER BY ShipToCode desc) AS [rn]
FROM t
)
Select * from cte WHERE [rn] = 1
2) Para eliminar el registro, use Eliminar consulta en lugar de Seleccionar y cambie la Cláusula Dónde a rn> 1. Sample SQL FIDDLE
WITH cte AS (
SELECT*,
row_number() OVER(PARTITION BY ARDivisionNo, CustomerNo ORDER BY ShipToCode desc) AS [rn]
FROM t
)
Delete from cte WHERE [rn] > 1;
select * from t;