Reset

On a PC, Control + Alt + Delete is used for various reset tasks.
On some PCs, this shortcut is used at start up in order to log on to the machine.
If you are already logged on, Control + Alt + Delete starts Windows Security, which lets you lock the computer, switch to a different user, log off, change password, start Task Manager, or shut down/reboot.
To use the Control + Alt + Delete shortcut, hold down the Control and Alt keys together, and then press the Delete key.