select a.Emp_Name, a.Company, a.Join_Date, a.Resigned_Date, a.RowNumber
from
(select Emp_Name
 ,Company
 ,Join_Date
 ,Resigned_Date
 ,ROW_NUMBER() over (partition by Emp_Name, Company, Join_Date
 ,Resigned_Date
 order by Emp_Name, Company, Join_Date
 ,Resigned_Date) RowNumber 
from Emp_Details) a
where a.RowNumber > 1