Process.Kill not working when publish code & using it in Cassini

In my code I m Creating Excel sheet but its process remains in task manager so I manually kill Excel process using Process.Kill()
but when I publish my code in cassini its not working.

Here is my code,
                DateTime dt = DateTime.Now;
                Process[] prs = Process.GetProcesses();                 List<int> excelPID = new List<int>();                                              foreach (Process p in prs)            ...