// Creating the Custom Tooltip
            m_toolTip = new ToolTip();
            m_toolTip.InitialDelay = 1000;  // duration of mouse hover before tooltip is shown
            m_toolTip.ReshowDelay = 1000;   // duration of mouse hover over 2nd control before tooltip is shown
            m_toolTip.AutoPopDelay = 20000; // duration tool tip is shown
            m_toolTip.OwnerDraw = true;
            m_toolTip.ShowAlways = true;
            m_toolTip.Draw += new DrawToolTipEventHandler(toolTip_Draw);
            m_toolTip.Popup += new PopupEventHandler(toolTip_Popup);

            // TreeView tooltips should not display
            myTreeView1.ShowNodeToolTips = false;

        // Handles drawing the ToolTip.
        private void toolTip_Draw(System.Object sender,
            System.Windows.Forms.DrawToolTipEventArgs e)
        {
            // Draw a custom background and text if the ToolTip is for treeview.
            if (e.AssociatedControl == myTreeView1)
            {
                // Draw the custom background.
                e.Graphics.FillRectangle(SystemBrushes.Info, e.Bounds);

                // Draw the standard border.
                e.DrawBorder();

                // Draw the custom text.
                // The using block will dispose the StringFormat automatically.
                using (StringFormat sf = new StringFormat())
                {
                    sf.Alignment = StringAlignment.Center;
                    sf.LineAlignment = StringAlignment.Center;
                    sf.HotkeyPrefix = System.Drawing.Text.HotkeyPrefix.None;
                    sf.FormatFlags = StringFormatFlags.NoWrap;
                    using (Font f = new Font("Microsoft Sans Serif", 12))
                    {
                        e.Graphics.DrawString(e.ToolTipText, f,
                            SystemBrushes.InfoText, e.Bounds, sf);
                    }
                }
            }
        }

        // Determines the correct size for the treeview ToolTip.
        private void toolTip_Popup(object sender, PopupEventArgs e)
        {
            if (e.AssociatedControl == myTreeView1)
            {
                using (Font f = new Font("Microsoft Sans Serif", 12))
                {
                    // Get tool tip text and add space to make sure the last character does not get trunctated
                    string tipText = m_toolTip.GetToolTip(e.AssociatedControl) + "  ";
                    e.ToolTipSize = TextRenderer.MeasureText(tipText, f);
                }
            }
        }

        private void myTreeView1_MouseMove(object sender, MouseEventArgs e)
        {

            // If the node is null, then the mouse is not over a node 
            // and the tool tip is set to be empty
            if (node == null)
            {
                m_toolTip.Hide(myTreeView1);
                m_toolTip.Active = false;
                m_toolTip.SetToolTip(myTreeView1, string.Empty);
            }
            else
            {

                // Set the tool tip to the Text of the node so that if a mouse hover
                // triggers the tool tip, the node's text is displayed.
                string nodeTip = node.Text;
                string currentTip = m_toolTip.GetToolTip(myTreeView1);
                // Only change the tool tip if the node text is populated 
                // and it isn't already set in the tool tip
                if (nodeTip != null)
                {
                    if ((!m_toolTip.Active) || (!nodeTip.Equals(currentTip)))
                    {
                        if (!nodeTip.Equals(currentTip))
                        {
                            m_toolTip.Hide(myTreeView1);
                        }
                        m_toolTip.Active = false;
                        m_toolTip.SetToolTip(myTreeView1, nodeTip);
                        m_toolTip.Active = true;
                    }
                }
            }
        }

This response contains a reference to a third party World Wide Web site. Microsoft is providing this information as a convenience to you. Microsoft does not control these sites and has not tested any software or information found on these sites; therefore, Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. There are inherent dangers in the use of any software found on the Internet, and Microsoft cautions you to make sure that you completely understand the risk before retrieving any software from the Internet.

This response contains a reference to a third party World Wide Web site. Microsoft is providing this information as a convenience to you. Microsoft does not control these sites and has not tested any software or information found on these sites; therefore, Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. There are inherent dangers in the use of any software found on the Internet, and Microsoft cautions you to make sure that you completely understand the risk before retrieving any software from the Internet.