How does my computer know when to activate the screensaver?
Your computer constantly monitors the activity going on between the various components of the system. When it notes that the keyboard and mouse have been idle for the amount of time indicated in the screensaver settings of the Display properties window, the system sends a special command to the foreground , or current, application to see if it can launch the screensaver. If an application is running that has a computer-based training (CBT) window open, or has a non-Windows program, such as one run from the MS-DOS prompt, as the foreground application, Windows will not start the screensaver. Here’s exactly what happens to start your screensaver: • To find out whether it can start the screensaver or not, Windows sends a message to the foreground application. This command is asking the application, “Can I start the screensaver?” • A non-Windows program will not understand the command, and therefore will not answer it. A CBT application will understand it, but will respond with a command t
