- Control–Alt–Delete (often abbreviated to Ctrl+Alt+Del, also known as the “three-finger salute”)
is a computer keyboard command on IBM PC compatible computers, invoked by pressing the Delete key while holding the Control and Alt keys: Ctrl+Alt+Delete. The function of the key combination differs depending on the context but it generally interrupts or facilitates interrupting a function. For instance, in pre-boot environment (before an operating system starts) or in DOS, Windows 3.0 and earlier versions of Windows or OS/2, the key combination reboots the computer. Starting with Windows 3.1, the command invokes a task manager or security related component that facilitates ending a Windows session.
- On some Linux-based operating systems including Ubuntu and Debian, Control+Alt+Delete is a shortcut for logging out.
On Ubuntu Server, it is used to reboot a computer without logging in.
- Ctrl+Alt+Delete is not a keyboard shortcut on macOS platforms. Instead, ⌘ Command+⌥ Option+Esc can be used to bring up the Force Quit Menu. However, in the macOS Server logon screen, pressing Control+⌥ Option+Delete (as the Option key is the equivalent of Alt key on a Mac keyboard) will show an alert saying “This is not DOS.”Control+⌘ Command+Power immediately restarts the computer.