Teamviewer stops working GetWindowText (User32.dll) Function

I have developed a C# code which access to user32.dll and it is using GetWindowText function. The code is working properly when Teamviewer is uninstalled on Windows 7.

However if you install Teamviewer, the code can not retrieve the text of control in window with GetWindowText function. The code is given below. How can I solve this problem ?

   [DllImport("user32.dll", CharSet = CharSet.Auto)]

   static extern IntPtr FindWindowExW(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, 

   string lpszWindow);

   [DllImport("user32.dll", CharSet = CharSet.Auto)]

   static extern IntPtr GetWindowText(IntPtr hwndParent, StringBuilder Wintxt, int txtsize);

   public void CloseWin(string param)

  {

    try

    {

     IntPtr hwnD = FindWindowExW(IntPtr.Zero, IntPtr.Zero, "CabinetWClass", null);

     IntPtr hwnD2 = FindWindowExW(hwDvar, IntPtr.Zero, "WorkerW", null);

     IntPtr hwnD3 = FindWindowExW(hwnD2, IntPtr.Zero, "ReBarWindow32", null);

     IntPtr hwnD4 = FindWindowExW(hwnD3, IntPtr.Zero, "Address Band Root", null);

     IntPtr hwnD5 = FindWindowExW(hwnD4, IntPtr.Zero, "msctls_progress32", null);

     IntPtr hwnD6 = FindWindowExW(hwnD5, IntPtr.Zero, "Breadcrumb Parent", null);

     IntPtr hwnD7 = FindWindowExW(hwnD6, IntPtr.Zero, "ToolbarWindow32", null);

     StringBuilder sb = new StringBuilder(255);

     GetWindowText(hwnD7, sb, 255);