Different laptops and PC brands use different Boot menu keys. Most modern laptops use the F12 key.
When you first power-on a computer, it goes through a very quick POST (power on self test). If you can hit the correct hotkey before the POST is completed (or hold it down as you hit the power button), you will get into the Boot menu. If you don't know the hotkey for your computer, you can look and see if a message comes up during POST, telling you what key to press.
Boot menu Keys by Manufacturer
Here's a list of common Boot menu keys by brand. Depending on the age of your model, the key may be different.
ACER: F12 or Ecs, F9
ASUS: Ecs or F8
COMPAQ: Esc or F9
HP: Esc or F9
LENOVO: F12 or Fn + F11, F8, F10
PACKARD BELL: F8
SAMSUNG: Esc or F12
SONY: F11 or F10
These instructions are used to run EQuilibrium from USB flash memory.
(You do this on your own responsibility, instructions are informative)
Change the boot order, like this:
Be careful when making changes to your settings there.