What happens when you press Ctrl-Alt-Delete?

David bradley (IBM Engineer) originally invented Control+Alt+Delete. Control+Alt+Delete is the combination of keys that the computer user can press at the same time to terminate an application task tor to reoot the operating system. In Windows 95 or any later systems, Control+Alt+Delete brings up a window that allows a user to see the status of all currently running programs and to terminate any of them, and also offers the options of shutting down, restating, Control+Alt+Delete is pressed a second time or twice in row quickly, the operating system closes all programs that are running and then restarts

When the buttons Control, Alt, and Delete are pressed at the same time on modern computers a screen pops up with several options including lock, switch user, sign out, change password, and task manager. On some systems, an option to shut down or restart is available. When pressing Control, Alt, and Delete several times in a row, the computer will shut down.

On earlier versions of Windows, this function was used mainly to see the task manager and end an unresponsive program. This combination of keys was designed by David Bradley, an IBM engineer. He has said on several occasions that he never meant for this key combination to be widely used.