You could try Pinvoke
[DllImport("user32.dll", SetLastError = false)]
static extern IntPtr GetDesktopWindow();
[DllImport("user32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool GetWindowRect(IntPtr hWnd, ref RECT lpRect);
RECT scBounds = new RECT();
GetWindowRect(GetDesktopWindow(), ref scBounds);