How to create a pc alarm using c#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Media;
using System.Globalization;
using System.Diagnostics;

namespace ALARM
{
    public partial class Alarm : Form
    {
        public Alarm()
        {
            InitializeComponent();
        }

        private void btnOpen_Click(object sender, EventArgs e)
        {
            bool isAlarmOk = true;

            while (isAlarmOk)
            {
                string dt = DateTime.Now.ToShortTimeString();
                
                if (string.Compare(dt,txtTime.Text) == 0)
                {
                    isAlarmOk = false;
                    SoundPlayer sp = new SoundPlayer();
                    sp.SoundLocation = @"C:\Users\Rahsan-PC\Documents\Visual Studio 2012\Projects\ALARM\ALARM\bin\Debug\sound\ding.wav";
                    sp.Load();
                    sp.PlaySync();
                    break;
                }
            }
        }

        private void btnClose_Click(object sender, EventArgs e)
        {
            timer1.Stop();
        }

        private void Alarm_Load(object sender, EventArgs e)
        {
            txtDay.Text = DateTime.Now.ToShortDateString();
            txtTime.Text = DateTime.Now.ToShortTimeString();
        }
    }
}