said by dave:Because having two discs is twice as safe as having one? You don't want to need to a system repair and then discover your only DVD had become unbootable.
My view, if I didn't use a server-based backup system, would be that for the price of a blank DVD there would be no reason to not make one.
But, of course, the option actually exists because not everyone has a retail DVD.
So OS Setup does include restore functionality? In that case why not just make a copy of OS setup disk?