 <p>1) use a timer with 15 seconds interval;</p> <p>2) save the current mouse location on screen: <a href="http://stackoverflow.com/questions/1316681/getting-mouse-position-in-c-sharp">Getting mouse position in c#</a></p> <p>3) when timer reached 15 seconds, check mouse location again. if it is changed, update current mouse location. if it is unchanged, draw something on screen at the mouse location (and you need clean it too): <a href="http://stackoverflow.com/questions/7897307/how-do-i-draw-graphics-in-c-sharp-without-a-form">How do I draw graphics in C# without a form</a></p> <p>It is not the best choice, but if the mouse is moved during the 15 seconds, it is unlikely it will back to its original location in 15 seconds.</p>