NICEVILLE, Fla. — In this week’s It’s Geek to Me, Jeff Werner answers a Shalimar reader who asks whether leaving a computer on overnight damages hardware or increases the risk of hackers gaining access.
Question:
Susan S. from Shalimar, Florida, writes:
Dear Geek, I’ve been having a bit of a debate with my spouse lately. Do I really need to turn my computer off every single night? I usually just leave it on so I can get right back to my solitaire game or my emails in the morning. But now I’m worried—is it damaging my screen to leave everything running all night long? And more importantly, is there a chance some bad guy could get into my system while I’m snoozing and not paying attention?
Answer:
Jeff Werner responds:
Well, Susan, you’ve hit on one of those “great debates” of the computing world, right up there with “Mac vs. PC” or “Does pineapple belong on pizza?” (I’m not going to take a stance on either of those, lest I cause the next great schism among internet users.)
If you ask around, you’ll find people who swear by the “Never Turn It Off” rule, claiming that the “thermal stress” of repeatedly heating up and cooling down will kill your hardware. Then you have the “Shut It Down Every Time” crowd who think their PC might melt down or spontaneously combust if left idle for more than twenty minutes.
Like so many of life’s little quandaries, the truth lies somewhere in the middle. Let’s break down your main concerns so you and your spouse can finally get some peace in your home, at least where this one issue is concerned.
Most of the concerns about power cycling have their roots back in the “old days” of computing—when a 20MB hard drive was the size of a shoebox. Back then, frequent power cycles actually could be hard on components. Modern hardware, however, is much more resilient.
Regularly shutting down your PC is actually beneficial for hardware longevity. It gives your cooling fans a break and reduces the total “on” time for your components. The impact of a restart is negligible.
Then there’s your operating system. Windows can be like a toddler; it gets cranky if it doesn’t get a nap. Shutting down and restarting clears out the cobwebs—temporary files, allocated system resources, memory leaks, etc. that cause your computer to operate at less-than-peak efficiency.
Finally, there’s energy usage. Even in Sleep Mode, your computer is sipping electricity. That may be a small issue to you, but multiply it by the billions of computers operating around the planet at any given moment, and it’s a noticeable environmental impact.
Shutting a system down completely not only lowers your energy bills, but it’s also better for the planet in general. As a compromise, if you step away from your computer for extended periods during the day, putting it to sleep is helpful. But if you’re done for the night, consider a full, graceful shutdown.
You asked if leaving the screen on all night is damaging. The short answer is that modern flat-panel displays (LCD or LED) don’t suffer from the same phosphor burn issues that plagued the cathode ray tube (CRT) technology used in older monitors. However, leaving even a modern monitor powered on 24/7 eventually does take a toll on the backlight.
Most monitors have a lifespan of about 30,000 to 50,000 hours. If you leave it on all night, every night, you’ll hit that limit years sooner than necessary. And for a huge percentage of the monitor’s life, nobody will have been looking at it.
Windows has some built-in tools to deal with this problem automatically. Just set your Power Options to turn off the display after 10 or 15 minutes of inactivity, and Windows will take care of the rest.
The part about internet bad guys working the midnight shift is the part that keeps most people up at night. Is your computer a sitting duck while you sleep?
Technically, the answer is “yes” because a computer that is on and connected to the internet is more vulnerable than one that is turned off. Hackers and automated “bots” are constantly scanning the internet for open doors. If your computer is off, that door is not just locked—it’s gone.
The one thing I can say in support of leaving a system running overnight is that this is when Windows usually installs updates and security patches, often forcing a reboot to make sure the updates are fully applied. If your system is offline, you might miss important updates, and then your attempt to protect your PC actually makes it more vulnerable.
Only you can choose exactly what’s right for you. If it makes a difference, I leave the computers for which I’m responsible on 24×7, but I keep pretty good tabs on system changes. And they get rebooted regularly to refresh their performance.
To view additional content, comment on articles, or submit a question, visit my website at ItsGeekToMe.co (not .com!)
Jeff Werner, a software engineer based in Niceville, Florida, has been writing his popular “It’s Geek to Me” tech column since 2007. He shares his expertise to help readers solve everyday tech challenges.







