Most of the work involved in installing Windows 8.1 takes place well before the installation software even approaches your computer. You have some research and planning to do, especially if you want to avoid spending a five-day weekend in Upgrade Hell.
For example, you must ensure that your PC is beefy enough to handle Windows 8.1. You also have to decide which of two types of installation you want to perform: an upgrade or a clean install. (More on this in a moment.)
If you opt for the clean install (a process that begins with erasing your hard drive completely), you must back up your data. Finally, you have to gather all the software bits and pieces you need in order to perform the installation.
Before you even buy a copy of Windows, your first order of business should be to check your computer against the list of hardware requirements for Windows, as published by Microsoft. Windows 8.1, as it turns out, requires some fairly decent memory, speed, disk space, and, above all, graphics-card horsepower. Most 2004-era computers (and earlier ones) aren’t up to the challenge.
A lower-powered computer can run Windows 8.1. It may feel slow, but you’ll get all the other security and feature enhancements.
The hardware requirements include a 1-gigahertz processor (or faster), 2 gigabytes of memory (or more), 20 gigabytes of free hard drive space (or more), and a graphics card that has “DirectX 9 support with WDDM 1.0 driver” (check the packaging or, for laptops, ...