Private Sub tv_Group_NodeCheck(ByVal Node As Object)
Node.Checked=False
End Sub

TIP
 --------------------------------------------------------------------------------
 
If you want to prevent the user from modifying the Checked state of a given Node 
object, you can't simply reset its Checked property within the NodeCheck event 
because all changes to this property are lost when the event procedure is exited. 
You can solve this problem by adding a Timer control on the form and writing this 
code: 
Dim CheckedNode As Node ' A form-level variable

Private Sub TreeView1_NodeCheck(ByVal Node As MSComctlLib.Node)

' Prevent the user from checking the first Node.
If Node.Index = 1 Then
' Remember which Node has been clicked on.
Set CheckedNode = Node
' Let the Timer routine do the job.
Timer1.Enabled = True
End If
End Sub

Private Sub Timer1_Timer()
' Reset the Checked property, and then go to sleep.
CheckedNode.Checked = False
Timer1.Enabled = False
End Sub


This technique is more effective if the Timer's Interval property is set to a small 
value, such as  10  milliseconds