Close dengan keyboard di vb.net

Assalamualaikum, salam sejahtera semuanya. saya mau nanya, saya sedang membuat program launcher chrome secara fullscreen dengan vb.net. saya mau ketika nanti chrome sdh berjalan user tidak bisa menutup chrome dg kombinasi ALT+F4 namun dengan CRTL+C. dan juga user tidak bisa membuka aplikasi lain. Bagaimana ya untuk implementasinya, saya sudah mencoba tp msh blm bisa sesuai dengan harapan saya. berikut koding saya:

Imports System.Runtime.InteropServices
Public Class Form1
    <DllImport("User32.dll")> Shared Function GetAsyncKeyState(ByVal vKey As System.Windows.Forms.Keys) As Short
    End Function
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Brun.Click
        Dim okcancel As String
        okcancel = MessageBox.Show("Xambrowser ini di buat oleh Syarif SMKIU, tekan OK untuk melanjutkan", "Informasi", MessageBoxButtons.OKCancel, MessageBoxIcon.Information)
        If okcancel = DialogResult.OK Then
            Dim ProcessProperties As New ProcessStartInfo("chrome.exe")
            ProcessProperties.Arguments = Turl.Text & " " & Targ.Text
            Dim myProcess As Process = Process.Start(ProcessProperties)

            Brun.Text = "Stop"
            Brun.ForeColor = Color.Green
            Me.KeyPreview = True
            Timer1.Start()

        End If
    End Sub

    Private Sub Form1_KeyDown(sender As Object, e As KeyEventArgs) Handles Me.KeyDown
        If e.Alt And e.KeyCode.ToString = "F" Then
            MessageBox.Show("terimakasih")
            Brun.Text = "RUN"
            Dim pProcess() As Process = System.Diagnostics.Process.GetProcessesByName("chrome")
            For Each p As Process In pProcess
                p.Kill()
            Next
        End If
    End Sub

    Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
        If GetAsyncKeyState(Keys.J) <> 0 Then
            MessageBox.Show("terimakasih")
            Brun.Text = "RUN"
            Dim pProcess() As Process = System.Diagnostics.Process.GetProcessesByName("chrome")
            For Each p As Process In pProcess
                p.Kill()
            Next
        End If
    End Sub
End Class