I also ought to learn how to spell bootable!!!!! I only have the 2 Bootable disc's that I keep safe and 1 backup of my C drive that I keep up to date on a second hard drive (internal) and a backup of windows that I keep on a DVD both of which I can access with the bootable media.
Yes, ISO as you mean a Acronis Image. ISO and Boot disc are not the same thing. You need to create the boot disc so you can load the Image from the Disc you put the Image on, after booting with the boot disc
so the boot disk is made and used to boot up, then the iso image is used, which has been stored on some other media, such as an external hd? i have previously been given to believe that the whole process, from booting to applying a backup, can be accomplished just with an external hd if you so wish?