It is something like:

Protected Overrides Sub OnDoubleClick(ByVal e As System.EventArgs)

If SelectedNode.GetType() Is GetType(TreeNode) Then
   CType(SelectedNode, TreeNode).Open()
End If

End Sub

Public Sub Open()
 System.Diagnostics.Process.Start([Node Name Here])
End Sub

-------------------

The above code is out of a control I created that extends the TreeView. The
'[Node Name Here]' is obviously the selected node name

You'll have to play around with the code slightly, but it should give you a
general idea.

Crouchie1998
BA (HONS) MCP MCSE

There is no easy way to differentiate the "+" from the remaining zone, but
anyway the "+" requires only a single click, not a double click. The code
below shows how to override the WM_LBUTTONDBLCLK event:

Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)

Const WM_LBUTTONDBLCLK As Integer = &H203

Dim bHandled As Boolean = False

Select Case m.Msg

 Case WM_LBUTTONDBLCLK
  Me.OnDoubleClick(EventArgs.Empty)
  bHandled = True

End Select

If Not bHandled Then
 MyBase.WndProc(m)
End If

End Sub

Dear Carlos, Dear Crouchie1998,
Thank you,