Guide : Hard Drive Window Mod

A few months ago I was intrigued by a small number of Hard Drive Modifications in which they put varied windows however none of which offered documentation on how they did such a mod, or even showed detailed instructions on how they did it. Now I've tried once before, on an aging hard drive and it was a dismal failure, after which many of my peers questioned my mental capacity claiming Hard Drives cannot be modified, and opening a drive in the open without being in a Clean Room would destroy the data on the drive and render it useless. Well, here arose the challenge, I had decided to prove them wrong...