If I buy a Window 7 system, can I back up the installation DVD to guard against the original disk becoming unreadable? If so how? I ask because years in the past, when I used NERO to make a CD copy of an XP CD installation disk, the second CD disk was not bootable. This hurt because when my original XP CD failed, I had to coerce MS to send me a new one. Pain. I think what I want to do is make an ISO image which when used to create a second installation disk, it will be bootable. Sound right? If I can do this, then I could store the ISO image file on a backup hard drive which I trust more than a DVD disk. I don't trust the shelf life of those disks any more. Well anyway, I tried Nero again on said old XP CD disk, and it generated an .nrg image file, which when I used it to burn a new CD disk, that disk would not boot either. Can someone advise how I can do what I need to do?