You would want Network Boot disabled by default, otherwise it'd be doing it every time you turned it on with a network cable plugged in. So you enable it, do the install, then disable it again.
D'oh. I am a muppet. Of course.

a 'tech talk' icon
Mine's the inside of one of my PCs, with some blur and softglow effects, the "Ball-tongue" font and then some glow effects applied to the font too ...