Solved windows update takes 25% of the cpu since today :(

Hello, today i found that at idle my cpu was at 25%-27% whereas before it would be at a few %..

i checked the ressource monitor and it shows that svchost.exe (netsvc) takes 25%...

I tried to look up the services in task manger and it shows several like : Aelookupscv, Browser, EapHost ,gpscv, Lanmanserveriphlpsvc, Profsvc,SENS, ShellHWdetection, Themes, Winmgmt, wuauserv.


i tried to desactivate wuauserv (windows update) and the cpu went back to normal....


Today is the day i get new updates but this cpu thing never happened before and usually i can see that i have updates available later in the day just when i check windows update (Then, when i click to download the updates i chose, my cpu usage goes up, i wait like 1 hour or 10 minutes and the updates are downloaded and installed).

But it didn't seem windows update was busy when i checked it ( it said no updates available) and the cpu was still at 25%..
Windows update is configured to "let me check to download the updates".

so what should i do? let things like that and reactivate windows update later in the day? Is it dangerous to let windows update off like i did?
Did i screw up my windows update by disabling the service wuauserv ?

THank you for your time

edit : i just checked windows update and it just said that no updates were avalaible to me. The cpu went back up (without any sings of windows update working) so i turned off wuaserv again to get rid of this cpu usage...

Also i have a question : if i click on "check for updates" will it try to search for all the updates that i hide? Or just the new ones? because i selected updates since january..

It is normal for wuauserv to take up 25-50-100 percent when searching for updates.

The problem is when it does this for hours and never stops, just keeps searching.

Is that your case? Was everything fine until yesterday? Did it search for updates and came up with results in few minutes?

If it was all good until recently and now it's stuck, you can try this:

Set Windows to Never check for updates.

Make sure wuauserv is not taking 25 percent of the cpu. If it does, just stop the service.

Download and install KB3168965.

Restart and set Windows to Check for updates but let me choose what to install.

Search for updates.

I believe it wasn't searching for updates
When it searches for update, you see it ("searching for updates") in the windows update window, right? But in this case windows update wasn't doing anything it seemed. Maybe i should have let it run a bit longer? it had been 2 hours since i booted the computer.

Right now if i check my windows update, the wuauserv is reactivated and the cpu goes to 25% but windows update doesn't seem to do anything (it is almost the time of the day when i can see the monthly updates ): i just see one update is availaible (the silverlight update that came a little earlier this month and that i haven't hide) on the menu but no sign of working.

The fact that this happens right at the day when usually my computers finds the monthly updates could be a reason for this?

Regarding your method, when i click "search for updates" will it try to gather all the updates i ignored and take a long time or will it just check the new ones ?
i might do that after i will try to install the monthly updates. Usually i do it the day after i can see them (thursday) so i can see if people have problems on some.
thank you for your answer

Have you do a google search "svchost.exe"

One of the result:
What is svchost.exe And Why Is It Running?

Do read and understand on this svchost.exe

Edited:
As for the windows update, it is better to use the Recommended choice.
If not your windows may have problems later.
Such as important updates.
As far as i understand, using this method; do not mean always checking for windows updates.

Not sure I understand your problem correctly.

You search for updates, searching completes with finding only Silverlight update and nothing else? And wuauserv still at 25 percent after search is complete?

Please do this - restart, then click search for updates. Allow 1-2 hours and please post a printscreen of the found updates.

Sorry if i'm not clear
I wasn't looking for updates, i just found that my computer at idles used 25% cpu which i could "solve" by disabling windows update (right click in the wuaserv service in the task manager).then cpu went back to normal.

Usually i never need to click the "search for updates" as it seems to find them suddenly and propose them to me in wednesday evening each month of the "updates day".

When i checked again windows update (by clicking on its icon on the config panel) , it just showed me a "normal windows update screen" with the silverlight update that was there since 10 days ( i didn't want to install it) without searching. i could have clicked "check for updates but i didn't and checked the cpu : 25%.which means that even while not searching windows update took too much cpu. (uaserv was back again of course in the task manager).

im going to do what you said; i clicked search for updates

Did you get a result? Or still searching?

If still searching, try the method i wrote above and hopefully it will solve your problem.

it is still searching and i have a feeling it could stay like this for long
the cpu usage didn't even go up from 25-27% when i clicked "search for updates", it stayed the same.

Setting windows update to "never check for updates" the cpu is still at 25%.. and windows updates keeps searching (it didn't interrupt the search). i had to stop the service as you wrote to get normal cpu usage.


Is KB3168965 the security updates of this month?

I also read about installing offline kb3102810 and reboot and check for updates...

which one should i do first? thank you for your help

It won't stop the search. You need to either restart and make sure it's stopped, or stop it yourself manually. Then set to "never check for updates", download and install. Every month lately when they release new updates, searches are very slow. This month's update that makes searches faster is the one I said. I can't guarantee it will work for you. For me it worked today. After searching for 5 hours for updates, I gave up, installed the update ending in 965, then in 5 mins it found the updates.

thank you; i think will do this tomorrow it's getting late and i prefer to do this with a fresh state of mind.

It's weird because for me it never really took that much time to find the updates; at most like 45 minutes and everything would go well.
And then suddenly today i get this problem^^

well i installed KB3168965 and now i cannot even open windows update
when i click on the icon in the control panel it says : "windows update has stopped working"

and i still have this 25% cpu taken by windows update even if windows update doesn't seem to work on anything...
if i disiable wuaserv, the cpu usage does down of course


edit : I cannot believe it 5 minutes after i write this i can open windows update and i can see this



and the cpu usage is normal!!!

Thank you a lot johnny20 i cannot believe that it actually resolved my problem^^

i'm going to install the updates then although the number is quite low? usually i get like 14..did you also have a low number of updates..

edit 2 : so i installed the updates and everything seems to work normally.
windows update doesn't take 25% of the cpu anymore

thank you again Johnny20.


so to summurize : install KB3168965 manually after disabling windows update; reboot and wait a bit; windows update found the updates on his own in 5 minutes.

You are welcome. I also got 7 updates only, low number. You should have waited a few days before installing, to make sure there are no problems with updates, but if you have no problems. then it should be fine.

yeah you are right
i wanted to put all this behind me^^^^
thanks again

Thank you johnny20, I was banging my head against the wall with this exact same issue and the kb3168965 update worked perfectly. I had gone through enough diagnostic steps (task manager, inspecting services running under the offending svchost process, running the resource monitor and seeing something funny in the wait chain, etc.) to figure out more-or-less what was causing the constant 25% cpu usage and knew it was something to do with windows update....

If I'm reading this situation correctly, windows update was hung up without the ability to check for updates properly because it lacked kb3168965, but without the ability to check for updates, my computer never knew it needed kb3168965. That's a very silly catch-22 on microsoft's part. The windows update diagnostic tool didn't catch the problem. The system update readiness tool wouldn't even run - it sat there spinning its wheels with no visible progress for several hours (far longer than the longest estimate I could find online).

Then I found this and manually installed kb3168965. I had to first disable windows update and disconnect from the net to prevent the problem from repeating itself during the manual install.... but 20 minutes later windows update is working great again. You're a lifesaver.

May I ask how you discovered this solution? How did you know to manually install kb3168965?

gregs said:

Thank you johnny20, I was banging my head against the wall with this exact same issue and the kb3168965 update worked perfectly. I had gone through enough diagnostic steps (task manager, inspecting services running under the offending svchost process, running the resource monitor and seeing something funny in the wait chain, etc.) to figure out more-or-less what was causing the constant 25% cpu usage and knew it was something to do with windows update....

If I'm reading this situation correctly, windows update was hung up without the ability to check for updates properly because it lacked kb3168965, but without the ability to check for updates, my computer never knew it needed kb3168965. That's a very silly catch-22 on microsoft's part. The windows update diagnostic tool didn't catch the problem. The system update readiness tool wouldn't even run - it sat there spinning its wheels with no visible progress for several hours (far longer than the longest estimate I could find online).

Then I found this and manually installed kb3168965. I had to first disable windows update and disconnect from the net to prevent the problem from repeating itself during the manual install.... but 20 minutes later windows update is working great again. You're a lifesaver.

May I ask how you discovered this solution? How did you know to manually install kb3168965?

Click to expand...

You are welcome, glad it worked for you

How did I know? Well, last April I upgraded from Vista to 7. It was a nightmare, I had all kinds of driver and bios problems, and also had to search, find, and install 5 years worth of win7 updates. Let's just say for a couple of weeks I spent hours every day doing this. I have become used with win7 problems, created accounts on many forums, looked for and shared solutions. This is not something new, it was the same for the last couple of months where you needed to install a certain update to make sure the search wouldn't take forever. First it was the kb ending in 812, then, last month the kb ending in 1664 if I remember correctly.

What I noticed, that on my other computer that is set to automatic install updates (recommended), the taking forever problem is not present. It's just on this laptop, that is set to "check for updates but let me decide what to download and install", every month the search would take hours and come with no results. I have no idea why. Is your computer set to "automatic" or "check but let me choose"?

"If I'm reading this situation correctly, windows update was hung up without the ability to check for updates properly because it lacked kb3168965, but without the ability to check for updates, my computer never knew it needed kb3168965"

It had the ability to check but probably it would have taken couple of days to come up with results. The kb just made the search faster.

It's set to check but let me decide whether to install.

This is a brand new machine with a factory install of win7 pro - and it runs great otherwise with plenty of memory, i5, ssd - so when update wasn't functioning it made me panic a bit. I use another win7 machine that has never - not even once - experienced this issue. After this week's patch tuesday that other machine found the updates almost immediately and I've never had to mess with it. So my panic was mostly caused by what I thought was a strange anomaly on this new machine (based on my small sample size of 2).

I realize I'm preaching to the choir but it's totally not acceptable for windows update to hog 25% of my cpu for multiple hours and not show any results for its efforts.... A few minutes while it's checking is acceptable and expected behavior.... Multiple hours (turning into days) is not ok.

25% is not that bad. I have an older laptop with 2 cores only, so mine was at 50%. Plus the usual web browsing, antivirus, it would stay at near 100 percent for hours while looking for updates.

Both your machines set to check but let me decide, but only one has the problem? Can you check whether on the machine that works fine KB3161608 is installed or not? This one is also known to solve the hung problem.

Yes, both are configured the same way but no, the one that has always worked well does not have the 1608 update installed. I can see it sitting there in the "optional" queue and yet it still works fine. Fingers crossed and knock on wood that that continues.... I've been running that machine for a few years now and it's been perfect every time. Never a problem. That one is a home premium sp1 desktop whereas my current "problem" machine is pro sp1 laptop.

Actually one other thing just occurred to me. On my perfectly-functioning desktop, I've never installed any "optional" updates. Only important security updates. Its queue of optional updates is horrendously long. On the new laptop, however (it's actually a factory refurb), I can tell you that the refurb techs went in and installed every available update (including the win10 nagware which I had to uninstall) after they loaded the OS and sp1. That would have brought the updates current as of about December of last year based on the update history. Might there be something in one of those optional updates from pre-2016 that messes with windows update? That's the one major difference I can think of right now between those two machines.