Windows Vista forum

General discussion

100 percent CPU usage caused by SVCHOST process, need help

by Lee Koo (ADMIN) CNET staff/forum admin / April 17, 2009 7:24 AM PDT

Hi, I am most frustrated by a process that takes the CPU to 100 percent use and then lets it drop back to about 50 percent every couple of seconds, which seems to run while my Vista 32BIT computer is idle with no programs actually running other than Windows. The usage report shows the offending "thing" to be "svchost," whatever that is-?but it can hog up to 78 percent of the CPU, making everything else run like it was an old 286! Can you please tell me what this process is? Is it something I can disable? How I can fix this very frustrating problem! Thank you.

Submitted by: James T.

Here are some featured member answers and link to articles to get you started, but
please read all the advice and suggestions that our
members have contributed to this question.

Possible Solution on 100 Percent CPU Utilization --Submitted by gwiljr

100 percent CPU usage caused by SVCHOST process --Submitted by callmebond

Check your system thoroughly for viruses and adware --Submitted by darrenforster99

Here's the solution --Submitted by chazzsubscribe

What is svchost.exe and why is it running?

Stop svchost.exe from stealing CPU cycles

Read all member contributions to this topic

If you have any additional advice for James, please click on the reply link and post it. Please be as detailed as possible in your answer. Thanks!
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Turn off some unnecessary windows services
by chadwicksean / April 17, 2009 10:48 AM PDT

In the control panel, you can select 'Administrative Tools > Services' and turn off some of those unnecessary services that run constantly. Just right click the ones that are not vital and select properties. Change the type to 'manual' from 'automatic' to prevent these services from starting up at boot time. Be careful not to turn off vital services like Windows and virus software components. Below is an old CNET article about turning off Windows XP services.


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Try identifying the related process
by Serenity3000 / April 17, 2009 11:03 AM PDT

Hello, James - svchost is a wrapper application used by system services. It sounds like your machine may be doing its normal indexing, but to find out which process is actually running inside the instance of svchost, right-click on the toolbar and select "Task Manager."

Click on the Processes tab and then click on the CPU column to sort by CPU activity. Find the svchost with the high CPU usuage, right-click its name, and then click "Go to services." It will switch to the Services tab, and the process involved with that copy of svchost will be highlighted. You may need to scroll down to it, but the left-hand column will show the name of the process.

If it's not apparent from the name and the description of the service, enter the process name in Google and do a search for it. Once you know the name of the service, you'll have a better chance of dealing with it.

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Try identifying the related process
by 7sinewave32 / April 24, 2009 1:25 PM PDT

> . . . right-click its name, and then click "Go to services."

When I right click on a service it only gives me:
"End process"
"End process tree"
"Debug" (greyed out)
"Set priority>"

Do I have to do some configuration to get "Go to services" ?

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Trojan or Virus problem
by GR-TEK / April 17, 2009 11:04 AM PDT

This problem is almost always caused by a Virus or trojan.
Even though you probably have an Anti-Virus program running, nothing is 100%.
The only way to deal with this problem is to do a full reinstall of Vista.
Below is a link to a site where they have step by step instructions on how to fully reinstall Vista

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Not always virus or trojan
by straussbyte / April 21, 2009 2:09 AM PDT

While this can indicate a virus or trojan, which is most likely using network services, it can be plenty of legitimate tasks as well. I wouldn't go straight to reinstall of the OS without at least looking around a little. I've actually seen this issue with svchost more often be legitimate tasks than malware. See my other post about using sysinternal tools to figure out what specific task is causing svchost to have high utilization. Even Windows auto updates can cause this problem, while it is downloading the patches.

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do a full reinstall of Vista
by boblasher / April 25, 2009 12:53 PM PDT

like cutting off your arm because you cut your finger badly.
How about attempting to scan and fix with all the tools that are available.
I had to reinstall xp 3 months ago and I'm still getting programs reinstalled that I lost. I work on my computer about 5 hours every day.

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No, You can't disable it!
by rumager / April 17, 2009 11:08 AM PDT

DHCP - Dynamic Host Configuration Protocol provides a framework for passing configuration information to hosts on a TCPIP network.

Go to Windows Website to fix it. I have a laptop here to fix that has 5 running but not, It's stopped and can't Manually start it. Admin. Password and the accounts don't match. The lady kept changing internet serve.It fouled it up. It's take it back to factory out of the box state. Goes to Windows Support and read the Bullitins and the registry hacks should help and if its a HP get rid of the HP Center?

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by OldPhotoBuff / April 17, 2009 11:16 AM PDT

That is a generic Host Process for Win32 Services. I don't use Windows 7 or even Vista - I still use XP. So, I have no idea why it should sop up so much CPU time. I used "What's Running" and in XP it occasionlly uses a very small bit of CPU time. I have, in fact 5 instances of it running, presumably for 5 different windows service running. I'd almost bet that some different program is used in Win7 and that this might just be left over from whatever (XP or Vista) you had before. Look in the Win 32 directory for it and maybe for something like it.

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100 percent CPU usage caused by SVCHOST process, need help
by jdp06 / April 17, 2009 11:18 AM PDT

You said you are using Vista?
That's the problem, get rid of it and use XP and your usage issues will be over!

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svchost problem happens with XP also
by TinaBelle / April 20, 2009 8:21 AM PDT

I'm running Windows XP and have the same exact problem. Although I know I'm not supposed to, I have several times just highlighted the offending svchost process and "stopped" it (sorry, I can't remember exact term). I get a warning not to do it, but I do and can get a few hours or more of better operating speed before it'll start interfering again. An earlier search faulted Norton 360 (which I do use) for the problem. But I haven't yet tried to uninstall it and won't until I'm sure Norton's to blame and/or I find a good cheap anti-virus substitute.

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svchost and Norton anti virus
by chrisglewis / April 24, 2009 12:16 PM PDT

I have had nothing but trouble with Norton anti virus so I have changed to AVG anti virus and Interner Security and I love it !!
It is available at I am using windows XP.

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by Tech Boy Stevo / April 24, 2009 12:58 PM PDT

Agreed. Norton is a resource hog that eats up memoory and computer usage. It bogs down Internet speed, and is the first thing I delete on a new computer.

Like you my wise friend - I use AVG Free. It has a small footprint, and has stopped every virus/trojan butt cold.

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If it is a virus...
by ChrisK1 / April 25, 2009 3:58 AM PDT

I had an actual rootkit that drove me nuts. AVG wouldn't touch it. I found one of the best programs on the planet as a result. It couldn't get rid off all the files, but, amazingly, it, at least, found them all! You can download it from CNet. Search Google for "malwarebytes free" and get it. If the SVCHOST thing isn't a virus, at least you got a really excellent malware program to supplement your virus scanner. It's really fast, too.

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Definately Norton
by nrogers69 / April 27, 2009 2:23 PM PDT

I actually had this exact same issue. It began when I installed what at the time was the latest Norton (2007) and went away when I uninstalled Norton and switched to Macafe. If you have Comcast internet service, they provide Macafe for free. I have had no viruses or svchost issues since.

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An exception
by MNBSwamy / April 27, 2009 4:07 PM PDT
In reply to: Definately Norton

I am also on XP and the problem is accute. But I am not having Norton on my machine.Anyway thanks for sharing your experioence so that I can try Mc'Cafe also.

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by DADSGETNDOWN / April 17, 2009 11:30 AM PDT

Don't know if this helps but I recall a Situation where there was a
SCVHOST, instead of the normal SVCHOST.
That would be some sort of infection I believe and there are fixes here on cnet and Virii, spyware, malware sites.
Hope this isn't it. Happy
Even though it's a pretty easy fix.

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by sian4fro / April 17, 2009 12:12 PM PDT

another interested reader also would appreciate response

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here's the solution
by chazzsubscribe / April 17, 2009 2:58 PM PDT
In reply to: svchost

There will be several instances of svchost running. As others have said it's a generic service that runs when some other application, service or even hardware is running.


Here's how. Microsoft has a free tool you can download, called Process Explorer. It's sort of like Task Manager but when you hover over each instance of SVCHOST, it will show you the associated tasks tied to each one. One innocent SVCHOST could be your modem. The "bad" one may be some software trying to check for updates via the internet. You could then disable that software and try to reinstall it.

it's NOT SVCHOST that is the problem. It's the underlying software, service, or even hardware that is causing that instance of SVCHOST to run so much.

Do a google search for Process Explorer. It's free from Microsoft. Download it and run it. See which SVCHOST is running the most and what is causing it.

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Windows Services using all CPU cycles...
by MarkinTO / April 24, 2009 2:20 PM PDT
In reply to: here's the solution

I've found that you 'must' have the latest version of Microsoft's Net Framework installed.

You might not have installed it, as a Windows Update or perhaps 'declined' that update option at some time?

You should have 3.5 SP.1

This allows for smooth up-dates to your OS.

It might 'not' fix your problem but, surely won't hurt to have this update!


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Thanx for SVCHOST problem solution.
by AHMADHAIDER / April 26, 2009 1:09 PM PDT
In reply to: here's the solution

Thanx again, for your solution, it worked much better for me.
Now my computer has become more faster after installing the Process Explorer.
I was not known to that software before this.

Thanx again.

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thank you very much!
by matplin / April 26, 2009 11:49 PM PDT
In reply to: here's the solution

I wonder why I did not check it before, while bothered every time by the CPU overload.
Thank you again!

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SVCHOST running at full CPU
by glenn9376 / April 17, 2009 12:20 PM PDT

if SVCHOST run at that speed when you are at idle it may be a trojan , and it sends outbound info such as passwords and such to another user. i sugest you run THREATFIRE or some such security program to catch it. or try a pre-boot scan using AVAST. hope this helps

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SVCHOST running at full CPU
by vattan2005 / April 24, 2009 1:18 PM PDT

Yeah, Threatfire is awesome behaviour-based software. That along with PCTools does the job for me.

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See attached website for a description of SVCHOST process
by JimLic / April 17, 2009 12:24 PM PDT
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100 percent CPU usage and SVCHOST
by robsb / April 17, 2009 12:46 PM PDT

SVCHOST is a process used by Norton. There is a known issue with this service and an incompatibility with Outlook Connect to Windows Live. Until the issue is resolved, Norton recommends either removing Outlook Connect or Nortons Add On Pack. I removed the Add On pack and the problem went away.

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excellent question
by benhartman / April 17, 2009 12:56 PM PDT

There are these nasty little (mostly legitimate, but annoying,) processes that run inside svchost processes.

Download a nifty utility from Microsoft (they usually have the cool tools to uncloak their own bad designs) called ProcessExplorer ( that shows you what actual processes are running inside.

In my case, it's usually Hewlett-Packard bloat-ware related to my hp printers. If it is something like a confused process, kill it by highlighting it and pressing Delete. (may have to run processexplorer by right-clicking on the icon and running as administrator)

Warning: It could be a fileIndexer from Google Desktop or Microsoft Index, an anti-virus scan or a backup process that is hogging resources, but they're not supposed to.

In my case, there's nothing an HP process could be doing that is so important.

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Zone alarm is the problem
by Golden swan / April 17, 2009 9:01 PM PDT
In reply to: excellent question

I have recently had this same problem, at first I thought it was a trojan, but it turned out to be a software conflict with the new versions of Zone Alarm & Avira 9.0 Antivirus.. I was loosing connectivity on my network after 3-5 mins and the computer was freezing svchost & DPC & hardware interupts were spiking the CPU to 98-100% I had to reset the network adapter for the CPU to return to normal, I unistalled Zone Alarm and all has been well for the last 3 day Happy hope this helps...

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100 percent CPU usage caused by SVCHOST process, need help
by pervaiz41 / April 17, 2009 1:00 PM PDT
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SVCHOST taking up CPU
by flaterry / April 17, 2009 1:05 PM PDT

For the in depth answer check out the link. The short version is svchost runs DLLs which are your programs such as spy ware protection and any other start up program. You have to many programs running at once which in turn eats up CPU use.

A simple way to remove them from the start up process is to use a freeware registry editing program called Quick StartUp. You can turn the ones off you don't need or turn them back on again if you change your mine. The link to get the program is

Florida Terry

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