Microsoft: Don't Switch Off PC At Night

John Lister's picture

Microsoft has warned users may need to leave computers on overnight to be sure of getting all security updates. It raises questions about how efficiently the update process works.

The warning comes in a company blog aimed at IT professionals, though the findings also apply to the general public. Whether to leave devices running is a particular issue in offices where it would make sense from a power use perspective to get staff to shut down their machines at the end of the working day, particularly if it's only used for around eight hours a day.

Microsoft says it's been investigating what may cause Windows computers to not be up to date with security patches and other performance fixes. It says one problem is a lack of "update connectivity", meaning the time the computer is switched on and connected to the Internet.

Outdated Machines Not Online Enough

According to the post, the minimum update connectivity required for a reliable update is two continuous hours to start off with, then a total of four further hours (which don't have to be continuous). While some of this involves updates installing in the background, the six-hour total is the minimum point at which the users can be sure the process is complete. (Source:

Based on remote data gathered from Windows 10 computers, this is likely a major cause of outdated machines. Microsoft says that of machines where the security patches are at least 60 days out of date, one in four didn't have enough update connectivity. (Source:

For those which are so outdated that they no longer run a "serviced build" of Windows 10 (also known as a Feature Update), the proportion without enough update connectivity rises to one in two.

Power Settings May Be 'Wrong'

Microsoft says IT staff should encourage staff "to leave their devices plugged in and connected - instead of powering them off overnight - so that updates can download and install properly. Impress upon them the importance of keeping their devices connected so their devices can stay protected and they can stay productive."

It also says that machines may be missing out on updates because their power settings put them into hibernation or "deep sleep" mode too quickly.

The counter-argument would be that six hours is too long for an update and it's a big ask to expect users to leave machines online longer. There's even an argument that doing so increases the potential risk of a computer being hit by a cyber attack.

What's Your Opinion?

Do you switch your PC off at night? Do you regularly leave it online for at least six hours? Is this a reasonable or realistic requirement by Microsoft?

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Average: 4.5 (11 votes)


doulosg's picture

After years of experience, I try to shut my electronics down at least once a day - at night, when I'm not using them. The daily reboot gives memory leaks a chance to recover, capacitors to discharge, processors to cool down, open activities to stop, etc. Not to mention the electricity that doesn't get used. The only time I do not is when I have work-in-process I cannot complete by end of day.

gmthomas44_4203's picture

I leave mine at "hibernate" over night, does that allow updates?
I don't know.

philipreeves46's picture

I leave my 2 computers on all the time, except for windows updates. I do this because I am a frustrated scientist. In other words if I could do the math that goes with it I would be one. So I have a program on my computer that allows scientists to use my computer to do things like look for ET, find cures for diseases, certain types of stars etc. Since there are probably scientists in many time zones, I leave them on so they can use them while they are idle and when I'm sleeping.

dbrumley3077's picture

I turn my computers off overnight. I think the potential of getting hacked increases the more your computer is online, plus I cannot justify the electrical usage if I am not actually using the computer.

ifopackets_10683's picture

Computer is fully functional at night BUT the Internet connection
is manually disabled.

I "work around" the update thing by being what MS calls a "Seeker".
In the little Win10 search box, type:
Check for Updates

Click on update link there to actually check.
Do not trust what you see when you first arrive there.
MUST be connected when you click OR Windows might tell you none are
available as of then (or some recent time).

It is very odd Windows is dumb enough to ignore the lack of a connection.
In farness to MS, there are scenarios where they complain about no connection,
but it is very easy for them to skip that part.

mike's picture

We have always turned our (desktop) computers and the internet access off when we are not using them, usually just before going to bed. If we leave for a couple of hours during the day, we leave the computers on but turn off the internet access. I figure that if I don't need the internet access, then the computer doesn't either. Before we retired, we usually didn't turn on our computers (and the internet) until we got home from work. I can't justify paying for the power to leave the computers on when I am not using them. We have never had any problems getting updates and we have been doing it this way since before Windows 95(when we had a dial up connection.) I see no reason to change it now. Our laptops get turned on when we need them and off when we don't and they have not had any problems either.
The only exception is usually when running a full system scan but then we turn off the internet.

SeaSteve's picture

I can see the point Microsoft is making about getting updates. I also understand users fear of the increased potential of being hacked when leaving a computer turned on when "not in use" but I've always look at this from a hardware prospective.

I'm a electronics engineer with 35+ years of experience in electronic component level trouble-shooting and repair and I've done FAR more repairs on equipment that's just been turned on than equipment that's been operating for months at a time....I guaranty that ALL electronic components fail due to a rapid temperature change. Turning OFF and ON electronic circuits causes components to fail prematurely because the components cool all the way down to room temperature then rapidly heat back up, at the circuit board level, to over 120 degrees. Failure can be prevented when electrical current keeps components at a proper operating temperature they are designed.

As a response to the 1st post...Capacitors discharge very rapidly once current stops in a circuit and a CPU chip will drop to a MUCH lower temp when the computer is idle or in standby.

I've always recommend leaving a computer on if it's used daily but turn it off if it's not used for three days or more.

doulosg's picture

Thanks for the information and the response to my rationale. Yours makes sense.

mike's picture

SeaSteve - I had not heard about the temperature changes when turning on and off computers - thanks for that information. Is turning a computer on in the morning and off at night and repeating every day that hard on the components? I understand not turning it on and off several times a day but wonder about once a day being harmefull...
My question concerns how much power a computer uses (or wastes) when not in use. I know the monitors are turned off after some time but the computer stays on...I have heard horrible stories concerning hibernation and thus I am unwilling to take any chances with it.

ifopackets_10683's picture

Mike, Hibernate is a setting that is optional. I disable hibernate and sleep.
I like a full(*) shutdown-turnoff better than both of those above.

I do have one computer that "runs" 24/7 BUT is only connected to the Internet
when I actually want to be connected.
I used to have a small timer program called "Internet off"
(Internet Off - Internet Blocking App for Windows - Crystal Rich)
but the MAX time was either 1 hr, or always on. Going overtime caused me posting
problems on Internet Help sites. So I only use the icon next to my clock on
the task bar now, manually.

(*)--A full shutdown is not what it used to be. That "cleaning functionality" was
replaced with "Restart", which obviously does shut you down AND restarts you,
and then FOLLOWED BY a MODERN "ShutDown". (Sounds odd to me also, Google it...)

russoule's picture

I have always understood that a computer, whether desktop or laptop, uses a msignificantly less amount of electricity than say a standard light bulb(not LED or any of the other bs type). So in terms of electric use and cost, I see no reason to turn the device off. In fact, I agree that the on/off action tends to wear out electronics much more quickly. However, with MS making the demand, I may change my system to disconnect the internet completely at night so those people can't get into my system. All I really need to do is pull the cable out of the router. Six hours for an update! Indeed! What a line of malarky. Windows can just download the update and then have the computer run that download at any time, just as other software does.