Disabling CheckBoxes

If I have 4 different CheckBoxes and when the user selects one of them I want the other 3 to become disabled so you can't click on a checkbox while another one is already checked how would I go about doing this? I have this, but it doesnt work right now and I thought it would:

    If NoDelayCheckMarkBox.Checked = True Then
        timeBetweenIterationDelay = 0
        SecondDelayCheckMarkBox.Enabled = False
        HalfSecondDelayCheckMarkBox.Enabled = False
        FiftyMSDelayCheckMarkBox.Enabled = False

I can still click as many check boxes as I want too. Thank you for any help.

As @brian already said, Radio buttons seem like a more organic way to achieve this result, but you still could do this with checkboxes if you wanted

Handle the CheckBox.CheckedChanged event with the same sub for all four checkboxes

<!-- language: lang-vb -->

Private Sub CheckBox1_CheckedChanged(sender As System.Object, e As System.EventArgs) _
    Handles CheckBox1.CheckedChanged, CheckBox2.CheckedChanged, CheckBox3.CheckedChanged, CheckBox4.CheckedChanged
    'cast sender
    Dim senderCheck As CheckBox = DirectCast(sender, CheckBox)

    'loop through all checkboxes
    For Each checkbox In {CheckBox1, CheckBox2, CheckBox3, CheckBox4}

        'only apply changes to non-sender  boxes
        If checkbox IsNot senderCheck Then

            'set property to opposite of sender so you can renable when unchecked
            checkbox.Enabled = Not senderCheck.Checked
        End If
    Next
End Sub