Recently, MS has started a crackdown on those who install the same OS on more than one computer. They've made it mandatory that each PC have its own separate OS installer etc. This is very impractical, not too mention expensive for owners of businesses (offices, schools, internet cafes, etc) dependent (or used to) on Windows OS. For example, each computer in your office would have to have its own separate OS, so you would have to buy an additional x number of installer packs instead of using just one for the entire lot. I am not a business owner, but I do know of some people who have been negatively affected by this.