I used to set up DVI on 1 monitor, and VGA on the other. however, that's probably too primitive...;)
Whatever monitor that got stuck on first usually wound up as the primary, but you could move the 2 displays around in Windows. (and that was back with XP)

I wish I'd said that.. The Staircase Wit

anahl nathrak uth vas betude doth yel dyenvey..;)