When should I turn off my computer?

This topic was recommended to me by a friend. She writes:

If you use a computer all the time, is it better to leave it on or shut it down each night? Does running a computer for long periods of time cause harm?

This is a very good question, and even people who have been using computers their entire lives are slightly confused on this topic, and with good reason!

It used to be that it was widely recommended to shut your computer down (aka turn it off) whenever you weren't using it- just like your car. You only left your computer on if you were going to be coming back to it soon. This was because older computers needed that break to clear out their RAM (see our last topic!), and they used a lot of electricity even when they were in "sleep mode" (more on that in a bit).

Nowadays, it's generally recommended to shut your computer down once a month, or if you won't be using it for a few days or more. I've had my own personal computer for almost five years now and it's only ever been turned off for about a month's worth of time in total, and most of that was when I was away on vacation.

Here's some quick terminology tidbits to help explain things:

• Shut Down- Completely turns the computer off. The computer has a routine it goes through before turning off (just like people do before going to bed), and then it stop taking in electricity. It's at this point that it's safe to unplug your computer from the wall.
• Sleep/Stand By- This mode can vary slightly between types of computers, but it does a good job of drawing it's own analogy. Just like how people don't completely stop all our functions while we're asleep, in sleep mode neither does the computer. The screen is dark, the computer isn't doing anything, but it can quickly be "woken up" by tapping a few keys on the keyboard or wiggling the mouse around. This is the mode generally recommended if you plan to return to your computer within 48 hours. (That's not a hard and fast rule, by the way, just a loose recommendation.)
• Screen Saver- The screen saver is the simple animation that shows up on your screen if you haven't interacted with your computer in awhile. The screen saver usually comes up before the computer goes to sleep. It's called a "screen saver" because it used to save your screen from getting what's known as "burn in". If a particular image was left on the screen of an older CRT monitor (the ones that looked boxier and were much heavier) , it would literally burn in, and no matter what you wanted to see later, you would always have the hint of that previous imagine there. Think of a double-exposed picture for any camera/film aficionados out there.
• Restart- Restarting tells your computer to shut down, but riiiiight before it powers off, to turn back on again. More on this later!

So why the switch? Sleep mode on most computers nowadays uses so little power that it's almost negligible, and most computers come with enough RAM that an average user can use the computer for long lengths of time without noticing a difference. That added with the increased attention of computer manufacturers to make computers that don't need to rest means that there are few reasons to turn off your computer, especially when it usually takes more electricity to turn a computer on than to leave it running in sleep mode for a few days.

Why turn it off at all then? Turning the computer off does still let it rest and clear out it's RAM- read the PTD (Practical Tip of the Day) for why that's important, but the biggest issue usually is safety. Don't worry, not for you, but for the computer. Coming from Florida, I'm used to having to go around the house and make sure all the electronics were turned off for the big thunder storms. If the power goes out when your computer is turned on, the computer will shut down without getting to go through it's routine. Imagine if you've ever gone to bed without getting to brush your teeth, check the doors, etc. You wake up feeling a bit off. Same with your computer!

Practical Tip of the Day:
Is your computer starting to slow down? It does take longer than normal to open a program or check a web page? Is it being cranky and not doing what you're telling it to? Try restarting your computer. By restarting, you're allowing the computer to shut down, clear out it's RAM, and then start again fresh. Restarting a computer is like letting your computer take a nap- it's only "asleep" for a few seconds, but just like that refreshed feeling you get after a short nap, your computer will be perkier, quicker, and ready to go after a quick restart!