From OpenSCADAWiki
Booting
To boot from the resulting "live disk" you need to reboot the computer and at the very start of loading to the stationary OS press the key to enter the BIOS boot menu and select our media (fig. 1). On different computers, the enter key to the boot menu may differ and be one of the following: "F8", "F9", "F10", "F11" or "F12". On some computers you can only change the boot order in the BIOS itself.