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Question

Svchost.exe is always consuming 50% or more of CPU

Jun 15, 2017 3:42PM PDT

What can i do to solve this? I try to finish that particular process with task manager and nothing at all happens. It's still there. I've read that svchost is a core program of the OS, but this never happened until now.

Discussion is locked

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Answer
Perfectly normal.
Jun 15, 2017 3:47PM PDT

To have several processes of Svchost.exe running. What's up?
Dafydd.

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Are you sure it's normal?
Jun 15, 2017 3:50PM PDT

Because when windows started it used to say 2-10% of CPU usage at best, but now it's 50%, or when i'm using only one program, it can raise up tp 80 or 100%. That can't be right.

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It's common, but no OK
Jun 16, 2017 7:28PM PDT

So I don't know if that qualifies as normal. Some process is bogging down your PC. I found it often with Windows Update causing it.

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Answer
I forgot to mention this...
Jun 15, 2017 3:47PM PDT

But when i click on "go to services" it shows the windows firewall, "Base filtering engine", and "Diagnostic directive service".

Oddly enough, when i open the control panel and select windows firewall, there's a message telling me that windows explorer has stopped.

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OK.
Jun 15, 2017 4:01PM PDT

When I checked in task manager, on my machine, I get 3-4%. This could be a browser ad-don or malware. You didn't mention Make,model or OS so this is a guess at best.
Dafydd.

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I'd check with Grif's advice.
Jun 15, 2017 4:16PM PDT
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hmm...
Jun 15, 2017 4:18PM PDT

My computer's OS is windows 7 home basic. I don't know the model... I mean in another thread they told me that it was a clone machine. But if it can be of some help, the motherboard is from ASUS.

I don't think it has to do with the browser, because sometimes it doesn't have that problem (and yes, i know that the title of my thread says "always", i meant most of the time.) and in these times, i have my browser, and a couple of programs opened at once, and it reachs 40% in the worst of cases.

Huh..... It just dissapeared without me doing anything... but still, what causes it to be at 50% of CPU, anyway?

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Curious
Jun 15, 2017 4:52PM PDT

Why do you have diagnostic services enabled?

On this w7 machine I see 4 services for diagnostics all of mine are disabled.
Nothing bad has happened.
Just a few less services taking up resources.

As for the firewall can you roll back to before this happened?

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Answer
While there is no one thing that can cause this.
Jun 15, 2017 4:21PM PDT

You can try Grif's usual scans noted in replies as well as a CHKDSK /F /R /X on all drives to rule out a few common causes.

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Answer
Ok, I'll try.
Jun 15, 2017 4:48PM PDT

Now that particular Svchost is back. I think it may be a virus or something.

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Answer
SVCHOST is one of those ...
Jun 16, 2017 4:46PM PDT

Nit dissimilar fron RUNDLL, SVCHOST is one of those system components that are used to run (and supervise?) certain different modules (in the case of RUNDLL, not too surprisingly, the modules are DLLs.)

The inconvenient part here is that you can't easily say what the modules being run are and what they are doing. Yes, they could be malware that is busy encrypting all your files as far as the eye can see, but they could also just be indexing or compressing your files. Is there a good deal of disk activity involved? They could also be encrypting your bitlocker protected drive, completely legitimately.

Of course there could also be something running in the background where your computer is busy as part of a compute grid, computing a missile trajectory to Betelgeuse or Alpha Cantauri - or helping out with a Denial of Service Attack against the email servers of the Democratic party (or someone else ...)

Running something like Process Explorer (from Sysinternals) might show you what module each instance of SVCHOST or RUNDLL active on your computer is busy running. That might give you a clue what is going on - in most cases I look at the directory where these modules are stored and that shows me what software package this is supposed to belong to.

By the way - when you find the task manager telling you something is 50% or 25% busy, that may just be its way of saying that one of your two or four processors is maxed out at 100%, meaning that the component doing this is in a flat out spin, busy without having to wait for any disk drive or network adapter.

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Answer
Might be Windows Update
Jun 16, 2017 5:04PM PDT

There was a well-known bug in Windows Update for Vista, 7, and 8 that caused it to behave like this when searching for new updates, which has only partially been fixed. Try temporarily setting it to never update, and then reboot, to see if this is the culprit. Google "windows update infinite loop" for plenty of fix suggestions.

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Try this
Jun 16, 2017 7:35PM PDT
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Not seen this for a while...
Jun 17, 2017 4:30AM PDT

...but I used to see it routinely during the time that Microsoft were "generously" offering us Windows 10 upgrades and screwing up Win7 Windows Update in the process! Haven't seen it or at least not noticably since the nagware went away.

SVCHOST, as you know is a service routine used by many Windows functions and Task Manager and Resource Manage (from the button on the Task Manager Performance tab) will usually show multiple instances. In my case, the heavy CPU soaker was always netsvcs (Resource Manager attributes the client where possible). The odd thing was that most times, I wasn't knowingly requesting netsvcs. On a single core machine, it would sometimes chew up 100% of the only thread. If I terminated the offending SVCHOST instance, sometimes some task or other would abort but often a new instance of SVCHOST(netsvcs) would start but rarely get higher than 40% CPU usage.

I never really got to the bottom of it and as I said, in my case, it seemed to go away. Hopefully you are up to date with your Windows patches, if not, catch up and see if that helps.