Windows is an event driven system and as such when an application is waiting for something to do, it should "go to sleep" until the Windows OS "tells" it that the user has done something of interest to the application (like clicked on a menu item) or that some other event of interest has occurred. The application then should "wake up" and deal with the event. If an application isn't doing anything "useful" such as responding to user input, printing, rendering, etc it shouldn't be spinning in a loop waiting to do something. This is not necessary under Windows and just wastes CPU time. Regards, Frederick C. Wilt