Answer:
F8
Step-by-step explanation:
In Windows PC (e.g Windows 7), Last Known Good Configuration, is an option that helps users to start up their PC if it doesn't start normally. This option is only accessible at boot process by using the keyboard (mouse will not work at this point). So to access this option, the F8 key is pressed repeatedly or held down. This will display some start up menus where the user can use the arrow keys to access the option.