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Should I turn my modem off when I'm not using my computer?

by winner2000 / January 21, 2006 1:49 AM PST

This is probably a stupid question, but I was just really curious to hear the answer.

I've had dial-up for the past 10 years or so, and just last week I (finally!) got high speed internet (via cable). I've "heard" that if you leave your modem on while you're not using your computer (if the computer is ON or OFF), hackers can hack into your computer during that idle time.

Is that true at all, or is it just silly? Thanks.

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It's true...
by John.Wilkinson / January 21, 2006 2:23 AM PST

Turning your modem off at night won't cause any problems, though it can be a hassle, especially when you forget to turn it back on and wonder why the internet's not working. (I've done that a few times.)

Now, as long as you are connected to the internet and your computer is on, there is a risk of you being hacked. Thus, some would advise you to turn it off at night, along with your computer. However, this is not necessary, just an extra precaution, as a good firewall, especially one that's hardware-based, should protect you.

Another factor is if you turn your computer off at night. If you do, and it's clean of malware, you can leave the modem on without worry. However, there are some types of malware that can set your computer to automatically turn on at, say, 3:17AM local time, communicate with the sender, and turn off before you wake up. Nice of them not to wake you, isn't it? Devil Therefore, if you're completely clean of malware and have a good security suite, you should be fine, but you can take the extra security precaution if you want.

Hope this helps,

P.S. This can also happen on dial-up, athough it would require you to either have stored the password or the program to have the ability to record your keystrokes and do it for you, which is a little trickier.

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by winner2000 / January 22, 2006 1:40 AM PST
In reply to: It's true...

...definitely sounds kind of scary now that I think about it, but I usually try my best to practice "safe-surfing" (i.e. regularly update virus protection, anti-spam, spyware software, keep on/maintain my firewall etc.)...hopefully that helps somewhat.

Thanks for your informative post though!

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Not an option for me...
by mwhitted / January 26, 2006 5:56 AM PST
In reply to: It's true... turn the modem off anyway. I have Vonage.

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alpha shield
by bandaid69 / January 26, 2006 7:07 AM PST
In reply to: It's true...

I have a little device called an Alpha shield that plugs in between the modem and the computer, pushing a little button effectively blocks all entry to and from the computer.

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alpha shield
by grayfrier / January 26, 2006 2:49 PM PST
In reply to: alpha shield

Can you tell more about alpha shield sounds like a product worth knowing of and could be very handy say if you need to shut down access in a hurry ?
could you please send some info to me at the least

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it's easier and cheaper
by wgself / January 26, 2006 10:05 PM PST
In reply to: alpha shield

Unplug the phone line.
Just as easy as pushing a button and a lot cheaper.
If you are using a dial-up modem and you have it configured to auto-answer you could be at risk. If you are only using the modem for internet access there is no reason to have auto answer enabled. I used a modem for twenty years with no problem.

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Norton Internet Security
by kidzdad / March 11, 2006 5:40 AM PST
In reply to: alpha shield

I have Norton Internet Security installed on my computer. It has an option to block all traffic if needed. Just another option.

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Alpha shield
by bandaid69 / February 22, 2007 8:45 PM PST
In reply to: alpha shield
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I Suggest A Power Control Center
by wjk / January 27, 2006 12:28 AM PST
In reply to: It's true...

I always leave my cable modem and router on. No hacker can get into my system or leave malware to turn on my computer at night while I'm fast asleep. There is no power going into my system. I have always used a power control center. This is a surge protector/power switch that sits under my monitor. Flip the master switch and everything powers up. After shuting down a flip of the switch disconnects everything on my system, printer, monitors, scanner, etc. This device has more then once protected my computer from surges.

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just dont worry
by jc1234 / January 29, 2006 7:09 AM PST
In reply to: It's true...

i just turn my computer off, after all only takes less than a minute to turn on but the modem is always on but i have bullguard and one of the option is to block traffic when bullguard is close , which is when it is off but just unplug both if you are worried as it isnt doing anything and saving power, and hepls the computer keep fresh

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turn off
by jc1234 / January 29, 2006 7:10 AM PST
In reply to: It's true...

i just turn my computer off, after all only takes less than a minute to turn on but the modem is always on but i have bullguard and one of the option is to block traffic when bullguard is close , which is when it is off but just unplug both if you are worried as it isnt doing anything and saving power, and hepls the computer keep fresh

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I forget to turn it back on ALL the time!
by amg503 / March 3, 2006 5:02 PM PST
In reply to: It's true...

I put my modem into "Standby" about 50% of the nights (I have a Motorola SURFBoard, so there's no "Off"), and I ALWAYS forget to turn it back on in the warning. Then, it takes about thirty seconds to get the juices flowing. That's a LONG time with cable internet!

By the way, I've NEVER been hacked when I left the modem on all night...

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Kobo ereader
by elmer2 / January 23, 2012 11:52 AM PST
In reply to: It's true...

My Kobo reader is really a tablet computer. I power it down at night and unplug the power supply. On at least 4 occasions it has lit up in the middle of the night (it has a backlight). My other computer network modem is on and the Kobo is connectable to that network. One night it flashed on and next day it had flipped forward 50 pages. Have heard of Ghost writers but ghost readers? Anybody explain this? No I am not kidding or paranoid

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by dgghostkilla / January 22, 2006 1:51 AM PST

dont worry about it. do you have a basic firewall? that would help. other than that dont worry about it

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Oh yea of great faith.
by maddogthegreat / January 26, 2006 7:06 AM PST
In reply to: no

Don't bet on anything. At least turn off the PC. I have my modem and monitor on a power strip so I can turn them off with one switch.

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Leave modem on, turn off computer
by dlauber / January 26, 2006 6:01 AM PST

No, a thousand times "no." There is absolutely no need for your to turn off (i.e. unplug) your DSL modem during the night. If you turn off your computer, nothing is going to get to you through the Internet. And unless you have gone into the BIOS and turned on the ability for peripherals to turn on your computer, no malware could conceivably turn on your computer, install itself, and turn off the computer while you sleep -- a great urban legend if there ever was one.

You would, however, be extremely prudent to connect your DSL modem to your computer through a router with a built-in firewall. I'd strongly recommend a Netgear router -- avoid Linksys like the plague (its tech support is about as incompetent as it gets). If you don't have any other computers on a network, just get an inexpensive Netgear router (often on sale for $29.95). It firewall will protect you.

Also, using Trend Micro's PC-Cillin Internet Security will give you an excellent two-way software firewall and virus protection, far superior to McAfee or Norton AntiVirus. IT also enables you to halt Internet traffic with one click of your mouse -- an easy safeguard when installing new software which requires you to disable your antivirus and other applications. And updates are easy compared to all the bugginess in Norton Antivirus.

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Modem vs. computer off/on
by Shutterbug / January 26, 2006 6:09 AM PST

It's a LOT easier to flip the switch off on the modem than to shut down the computer (time time time getting back in). I have the TCP/IP ports "unbound" in MyNetwork so I am protected from backdoor viruses getting to me. I've had only two in e-mail since June of last year due to this handy little bit of knowledge I found. My old modem had no switch. Someone got smart (Westall) and put an on/off switch on the DSL modem. PTL!!!

I was told hitting the on button to a computer all the time (day after day) can wear out the switch. I just have the monitor turn off with mouse movement turning it on. But to have to wait an eternity for Windows and all my other programs to load would surely try my patience to the nth. I would only turn it off if I were going to be gone for a while.

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Turning computer off
by shanedr-19643301445202407030508154978607 / January 26, 2006 6:33 AM PST

I suggest you rethink turning your computer off at least once every 24 hours. For some reason windows works better if it boots daily. I use standby during the day (sleep button on keyboard) and a full shut down at night. Although I used to use standby all the time and a reboot every week or two.

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PC is off when not in use.
by Brianstech / January 27, 2006 1:13 AM PST

I just can't understand leaving a computer on all the time. Hard drives, power supplies, fans, you name it, they all have a limited life expectancy. Many times too short for my liking.

When you spend hundreds on a video card, just the fan alone only is good for so many hours. I have a stack of bad hard drives I pulled out of client's computers. Everything wears out faster from constant usage. It's too expensive for me to leave my PC's running 24 hours a day.

As far as time spent shutting down and starting up, you have other problems. Mine take about 45 seconds each. Tons of security, printing, scanning, editing (photo, video, and audio), TV tuner, you name it. I will NOT allow them to load with Windows. The only thing I allow is my Claw controller, and it doesn't use any resources.

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leave modem ON, turn OFF computer
by jasch / January 27, 2006 1:54 AM PST

Has anybody heard of Zone Alarm, great protector and it has a feature to block internet activity,just click on the open padlock and no signal will enter into your computer.

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Computer off, no problem but...
by joneso / January 26, 2006 7:24 AM PST

There are a number of reasons why not to turn off the ISP-modem but, if the computer is off, hackers can not get at it through an on-modem. And, if you have good antivirus/antispyware software they should prevent anything from getting in when the computer boots.

But...computers can be configured to turn on when tickled by the network so make sure this option is not enabled in the main or network BIOS. Otherwise, the machine could be turned on, cracked, then turned off.

Good idea is to put a router such as provided by Netgear between the modem and the computer for a couple of reasons. First, there are built-in firewalls in the router that can help. Secondly, you can configure the router to do the automatic connection with the ISP provider BUT specify fixed IP address(es) for your computer(s). Then choose the string 10.x.x.x or (if I recall correctly) 192.x.x.x as your internal domain string, the last "x" being 1, 2, 3, ... for each device on your internal lan. The outside world can not resolve these (private) domains so it is, I believe, impossible for anyone in the outside world to see anything on your LAN string. In this case, you can leave all hardware on 24/7/365 if you choose. I have used 10.x.x.x for years with 24/7 computer operation and never had a problem and never had anything but a "no possible connection" when security is tested by an outside source.

But...I agree, booting Windows regularly helps keep the squirrels at bay. So...

1. Keep auto-turn-on option off;
2. Install a router;
3. Set up a private internal LAN;
4. Boot Windows regularly...once a day is good.


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Unplug it
by Just Billy / January 26, 2006 7:46 AM PST

I do not trust the best firewall, nor do I think my computer is always free of a program to "dial out".
I just unplug my "jack" connection to the computer. It just takes a second, and a new connector cord (if needed)is cheaper than a switch.

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Computer off
by Jakable / January 26, 2006 7:54 AM PST
In reply to: Unplug it

I have had Six home PCs and four at work and never once have any of them been comrpomised from outside. A good firewall does the trick. A router gives added protection.
There is no problem with rebooting. Waiting for programs to load in good patience training. I have yet to wear out a switch on any computer and had one at work, which I turned off at the end of every shift for 8 years.

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Switches do fail.
by kndlewis / January 26, 2006 10:31 PM PST
In reply to: Computer off

I was turning off the modem when not in use when I first got Broadband until the switch on the modem failed! I managed to get it to turn on by opening it up so needless to say, I do NOT turn the modem off any more.
We do, however, shut down the computer when not in use.

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Me too
by winged foot / January 26, 2006 6:47 PM PST
In reply to: Unplug it

If I turn my modem off, I think I'll loose my phone and cable - all linked through RR, so I just unplug. Works fine as far as I know.

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Leave modem on . . .
by Oclvroadbikerider / January 26, 2006 8:45 AM PST

There is no need to turn the modem off. I keep the modem and router(either hardwired or wireless/combo) in a central house location on a seperate surge protector. They stay on all the time and only recycled if the ISP connection is dropped.

Computers are usually turned off when not being used. I'm NOT worried about wearing out the switch's!

However I'm really surprised NO ONE else has mentioned Hibernating your system when not in use. Most modern desktops as well as laptops have the ability to hibernate (I set the default for my power switch for both). With hibernation you can power down the system, yet retain a copy of memory including all open programs, webpages, the operating system etc, that LOAD MUCH FASTER than a reboot.

As others have mentioned, it IS a good idea to periodically do a normal shutdown and reboot of the OS to get rid of accumulated garbage that only a reboot will do. I reboot at least once a week.

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Put modem on standby if you have this option
by haroldino / January 26, 2006 9:01 AM PST

Putting modem on standby is a good option. Turning computer or modem off is safe

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Not necessary to turn off
by jazzy5 / January 26, 2006 9:27 AM PST

Here is the deal. All past suggestion given before are good. Just pick the one you feel more comfortable with. But from my experience, this is what I do. I leave my computer on all day and turn if off at night. This is because for the next 8 to 10 hours nobody will use the computer. I might save a few cents on electricity but also I might save my computer especially the hard drive from damage. You never know what my happen at the middle of the night.

During the day all my computer are running and protected from my modern/router with firewall. I also have Zone Alarm as additional firewall. If I have to go out for more than an hour, I tell Zone Alarm to stop all internet activity and to engage Internet lock. Nothing will come or go. If you practice safe computing (Update anti-virus, firewall, anti-spam and not opening attachment, carefull what you download or install) you will have no problem from your computer calling a hacker so he can take over your computer.

Your can test your computer to see if it is invisible to any hacker by going to Steve Gibson site ( and test you connection. This way you can close any port that might be open and block the ability of any hacker take over your computer.

BTW, one of my computer, which I build in 1995, I turn it on and off and the switch has not broken yet. It runs on a 500 Mhz K-6 AMD chip. But I do save some dollars by turning off all 4 computers at night.

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This is NOT a stupid question.
by fixers29 / January 26, 2006 9:42 AM PST

Have been wondering what happens when I have to redo my computer. Sometimes I run for a long time without a firewall while setting up programs. (I have DSL) I know that I can turn off my modem, I always seem to forget that, also lots of programs want to have internet access while installing.
Once your firewall is set up I think you are OK. The second program I set up is Norton and let the Pete do its thing. After that I am reasonably sure no virus is left. Now, whether I leave my modem on or shut it off never seems to make any difference.
If anyone can give a more technical explanation, please do.


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by mikeoboy / January 26, 2006 10:24 AM PST

Many, many people say that they have no virus problems simply because their antivirus programme reports nothing - oh how many times have I replaced thought-to-be-good programmes on buddies' computers with N

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