How to Make Your Computer Meaningfully Faster

There are many people who have many incorrect (largely outdated) ideas about how to make their computers faster. In my experience as someone who works at a business that repairs computers and makes them faster, there are a limited number of things that will effectively improve your computer's speed.

This resource is for your bog standard windows computer; I don't know much about gaming computers and I can't help you make yours faster. If you're wondering "But what about Apple?" there is a rather comprehensive answer for you at the link.