Form is freezing when using timer

Hi all..

I am having some problems with my code.
I need a textbox to update the CPU current speed. Only problem is that
the form itself freezes when I use a normal timer.

The timer updates every 500 ms... 

How else should I attack this problem?


//Code

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Management;
using Microsoft.Win32;

namespace HardwareMonitor
{
    public partial class SystemMonitor : Form
    {
        ManagementObject MO = new ManagementObject("Win32_processor.DeviceID='CPU0'");

        delegate void DelegateUpdate();

        public SystemMonitor()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            //CPU Name
            string CPUName = (string)(MO["Name"]);
            txtCPUName.Text = CPUName;
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            DelegateUpdate delegat = new DelegateUpdate ( () =>
                {
                    //CPU speed using WMI. Win32_processor.DeviceID
           
                    uint speed = (uint)(MO["CurrentClockSpeed"]);
                    txtCurrentSpeed.Text = Convert.ToString(speed) + " MHz";

                    //CPU Core Voltage
                    UInt16 CurrentVoltageRaw = (UInt16)(MO["CurrentVoltage"]);
                    //Devide the voltage by 10 to get the real value
                    double CurrentVoltage = Convert.ToDouble(CurrentVoltageRaw);
                    CurrentVoltage /= 10;
                    txtCoreVoltage.Text = Convert.ToString(CurrentVoltage) + " V";
                   
                    MO.Dispose();
                });

            txtCoreVoltage.Invoke(delegat);
            txtCurrentSpeed.Invoke(delegat);

           
        }

        private void exitToolStripMenuItem_Click(object sender, EventArgs e)
        {
            timer1.Enabled = false;
            Close();
        }

        private void btnCheck_Click(object sender, EventArgs e)
        {
            timer1.Enabled = true;
        }
    }
}