Originally posted by GeeYouEye
A number of reasons:
1. Because I've used the disk as a middleman for cloning a disk, and because I've used it as a backup before reformatting a drive with a screwed up system, I have probably half a dozen working and non-working OS's, ranging from 8.6.1 to 9.2.2, and from 10.0.3 to 10.2.1.