How to close a application which s running in Task Manager Application tab not process Tab

Hashtable objhashProcess = new Hashtable();
Hashtable objHashProcess1 = new Hashtable();

protected void CheckExcelProcess(int call)
    {
        try
        {
            if (call == 1)
            {
                int iCount = 0;
                Process[] ps = Process.GetProcesses();
                foreach (Process p in ps)
                {
                    if (p.ProcessName.ToLower().Equals("excel"))
                    {
                        objhashProcess.Add(p.Id, iCount);
                        iCount++;
                    }
                }
            }
            else if (call == 2)
            {
                int icount = 0;
                Process[] ps = Process.GetProcesses();
                foreach (Process p in ps)
                {
                    if (p.ProcessName.ToLower().Equals("excel"))
                    {
                        if (!objhashProcess.Contains(p.Id))
                        {
                            objHashProcess1.Add(p.Id, icount);
                            icount++;
                        }
                    }
                }
            }
        }
        catch (Exception ex)
        {
            lblError.Text = ex.Message;
        }
    }

protected void killProcess()
    {
        try
        {
            Process[] ps = Process.GetProcesses();
            foreach (Process p in ps)
            {
                if (p.ProcessName.ToLower().Equals("excel"))
                {
                    if (objHashProcess1.Contains(p.Id))
                    {
                        p.Kill();
                    }
                }
            }
        }
        catch (Exception ex)
        {
            lblError.Text = ex.Message;
        }
    }

string bookTitle = "titleOfThePdfToBeRemoved"; // The pdf title that you want to close.
 Process[] AllProcesses = Process.GetProcessesByName("pdf");
 foreach (var process in AllProcesses)
 {
    string tempTitle = process.MainWindowTitle.Split('-')[1].TrimStart();
    if (bookTitle == tempTitle)
        {
            process.Kill();
        }
 }