Need to reboot sony viao laptop busted screen

i have a sony viao laptop, i dont have the reboot disk but i know how to get to the reboot menu, the screen on the laptop is completely useless tho and im using an external monitor, whenever i go to the reboot menu it only lets me use the laptop screen, i somehow luckily get out of the reboot menu and get the laptop to go back to working like it is whereas i can use it to go online and do basic necessities but i need to reboot it to factory settings cause it has many problems, is there a way i can get the reboot menu to work on the external monitor so i can actually get through the whole process?