We have received so many problems regarding several windows and third party process which may hang sometimes and goes into not responding state which in turn create a problem as no other process respond to user mouse action at that point of time.
In such a type of situation a free program like Daphne can be very useful to kill the not responding or hanged process which has caused the whole trouble. Daphne is a small system tray application which can be used for killing, controlling and debugging windows process.
You can kill any process by dragging the mouse over windows, right clicking the process in the Daphne process list and select end process. It can also be used to set any window to be on the top, to be transparent or to be enabled.
source: www.troublefixers.com