static Process[] process;
        public static void KillProcess()
        {
            process = System.Diagnostics.Process.GetProcesses();
            foreach (Process p in process)
            {
                if (p.ProcessName.ToLower() == "excel")
                {
                    p.Kill();
                }
            }
        }

------解决方案--------------------

        public void Kill()
       {
          Process[] process = System.Diagnostics.Process.GetProcesses();
           foreach (Process p in process)
           {
               if (p.ProcessName.ToLower() == "winword")
               {
                   p.Kill();
               }
           }
       }