Recently one of my friends, a computer wizard, paid me a visit. I mentioned that I had recently installed Windows on my PC, told him how happy I was with this operating system and showed him the Windows CD. To my astonishment and distress he threw it into my micro-wave oven and turned it on. I was upset because the CD had become precious to me, but he said “Do not worry, it is unharmed.” After a few minutes he took the CD out, gave it to me and said “Take a close look at it.” To my surprise...