How to roll back your Windows 10 upgrade

Hundreds of millions of Windows 10 users can’t be wrong -- or can they? I hear from people every day who tried the Win10 upgrade and for a variety of reasons -- broken drivers, incompatible programs, unfamiliarity, fear of snooping, doubt about Win10’s future -- want to get back to their good ol’ Windows 7 or 8.1.
If you performed an upgrade using Microsoft’s tools and anointed techniques, rolling back should be easy. Operative term: “should.” Unfortunately,