This book is aimed at the great average middle of computer users, proficient but by no means a technician. You are not stuck with Windows or Mac. You don't have to surrender to the profit-driven upgrade cycle. You can still use your computer and keep it secure and gain a measure of control you could not otherwise have. The answer is replacing Windows with Linux (it runs on Macs, too). It's quite possible the average computer user can learn to install and run Debian with at least as much savvy as you ran Windows. You don't have to become a computer technician to understand it; it's not that hard. This book covers installing Debian 8 (Jessie).