Forgot to past the script:

DELETE D FROM

(

SELECT ProductName, ROW_NUMBER()OVER(ORDER BY ProductName) AS RowNum

FROM dbo.T1

) as D

JOIN

(

SELECT ProductName, ROW_NUMBER()OVER(ORDER BY ProductName) AS RowNum

FROM T1

) as E

on D.ProductName = E.ProductName

AND D.RowNum < E.RowNum