
Everybody's got an opinion on how to keep a Windows system running fast and smooth. Some tips are timeless, others are bunk that always recirculate. Here's a closer look at what really helps and hurts your Windows PC.
First up, here's the quick chart version, with the tips you're likely to hear floating around the net and from the mouths of casual IT types; each tip is plotted by its reputation and actual value. (More details for how we assigned these values below.) Click the image for a larger view.

And now a little finer explanation on those points.
Seems Bad, Is Good

These are those tips that seem like they actually kind of suck, but are in reality pretty good for your system.
Sleeping/Hibernating Instead of Shutting Down: Knowing that your laptop is drawing even just a trickle of power can freak out anyone who's had to pay for an expensive battery replacement, so a lot of people think it's always better to shut down your system when you're not using it. If we're talking PCs, the answer to the question of sleep or shutdown depends on how you feel about your electricity bill. For laptops, the issue of battery life and convenience is a sticky wicket. It takes some time and some vigorous hardware use to boot up your system, so if you know you're only stepping away from your system for, say, less than 3 hours, go ahead and close the lid and suspend it, or hibernate your system if you find it faster starting up. If you're going to be away for a solid bit, shut it down. Either way, don't plug it in if you don't have to, and spend more time getting things done than micro-managing your modern battery.