Recently, I have purchased iMac with Lion pre-installed. I would like to create a bootable DVD as a back up. However, I was unable to find guides that teaches how to do it. So far, what i have managed to find are the guides that allowed user create bootable OS from app store and not from preinstalled Mac. So may I ask if anyone down here has any idea how to do it? In addition, how do I know my lion software key from an pre installed lion mac? Thanks!