The Short Version:
Is Windows sucking up CPU power on your machine for no apparent reason whatsoever?
Here’s how I stop it on my computer.
- Open up Task Manager (CTRL+SHIFT+ESC).
- Click “CPU” to sort processes by CPU usage.
- Select the one that says “Service Host” — usually “Service Host: Local System (Network Restricted) (Number)“. The processes will move up and down, making this a bit tricky, but you can do it!
- Right-click it and select “End task”.
- A dialog box will pop up, warning you that the world will end, but check the little disclaimer box and click “Shut down”.
99% of the time, the only thing that happens is CPU usage goes back to normal.
There was that one time where I had a blue screen a minute later … but it’s only happened once.
In my opinion, it’s an acceptable risk, as the only other solution I’ve found so far is rebooting anyway!
The Full Story:
A few months ago, I decided to take the risk and upgrade to Windows 8.1.
(See, I usually like to wait a least a year before doing things like that, to give the company time to work out the bugs… well, I suppose I was feeling a little adventurous.)
Shortly after doing the upgrade, I noticed the CPU would occasionally start running at 10% to 20%, like so:
There was no reason. It appeared to be doing nothing whatsoever. It wasn’t a result of me opening a program, closing a program, or anything. Just one moment it wasn’t wasting resources, and one moment it was.
I opened Resource Monitor. I opened Task Manager. I opened Process Explorer. None of them could tell me anything, except that Service Host was the culprit.
I Googled. I read forums. I read articles. None of them could tell me anything useful.
I opened up the Services window, and once I even went to kill every single service that Windows would permit me to.
It took forever, and when I was done… well, the computer was still sitting there wasting resources.
So, whenever it happened, I would just reboot. Save all my work, close all my programs, and reboot.
Pain in the ass.
Sometimes, when I told it to reboot, the computer would just sit there with a blank screen saying “Restarting” while the little spinny animation went on forever and ever. Sometimes I’d have to unplug the thing and remove the battery just to get it to reboot!
It was maddening.
And THEN! The other day, I had a bright idea.
I opened up Task Manager (CTRL+SHIFT+ESC), and sorted processes by CPU usage.
Crap. It’s Service Host. Well, there’s nothing I can do about that, right? Service Host, as we all know, is a crucial Windows process that can’t be closed.
In a wild case of neuron misfire, I found myself right-clicking the process and hovering my mouse over “End task”.
Well that’s weird. I wonder what might happen if I did this?
I clicked … and was presented with a friendly warning:
Alright. Let’s do it. I’m at the end of my rope, and about to throw my computer out the window, because I don’t know what else to do.
I clicked “Shut down” and waited for the world to end.
A moment later, I realized I was still alive … and, to my delight, found that my CPU usage had returned to normal.
It was crazy. Wild. Amazing. How did I not think of this months ago?
And, while my problem hasn’t gone away — I still have no idea which service, exactly, is responsible for this needless waste — I’m happy to not have to reboot any more.
(Well, there was that one time where I got a blue screen about a minute after killing the task … but, as I see it, I would have had to reboot anyway.)
Maybe next time it happens, I’ll go through the CRAZY-long list of services Process Explorer tells me about, and kill them one by one … but, most likely not. I’ve got better things to do!
i also face this problem, so i simply uninstall windows 8.1 and start using win 7.
another solution use Linux.
Windows is not stable, whats it do in background that only microsoft knows….
(Updated previous post) – Initially I had the System Idle Process constantly at ~25% CPU. I ran (in the console as admin) “sfc /verifyonly” & “sfc /scannow” – both showed no OS or system integrity errors/problems. So I killed the System Idle Process (in Task Manager) & rebooted, then I saw the System process at ~25% CPU (System Idle Process had disappeared). Waited a couple of days (rebooted 2-3 times) hoping it would resolve on its own, did not. Then rebooted in diagnostic mode (press F2 quickly just as it starts booting up), did not run any diagnostic, just looked around, then hit Esc to exit & let it complete its bootup process. The 25% CPU problem was solved, there was no System Idle Process & the System process was at 0.4% CPU. All is back to normal, no idea why this worked !
Initially I had the System Idle Process constantly at ~25% CPU. I killed it (in Task Manager) & rebooted, then I saw the System process at ~25% CPU (System Idle Process had disappeared). Waited a couple of days (rebooted 2-3 times) hoping it would resolve on its own, did not. Then rebooted in diagnostic mode (press F2 quickly just as it starts booting up), did not run any diagnostic, just looked around, then hit Esc to exit & let it complete its bootup process. The 25% CPU problem was solved, there was no System Idle Process & the System process was at 0.4% CPU. All is back to normal, no idea why this worked !
sometimes the windows update service uses a lot of cpu too… In my case it was using upto 24%
I bought this computer with 8.1 and it’s slower than my old Windows 7. Go figure!! I’m going to look into the info given here. Thank you!!
Egore Rosbock, III
XDude says . . . at August 22, 2016 at 10:02 AM
I bought a new computer with Windows 8.1 already installed on it and it has been doing the CPU hogging all along.
I tried what the story say a while later it keeps happening again and again and again now what?
In other news, I haven’t actually encountered the CPU-waste problem at all on my new computer, which I’ve been using for 8 months and also has Windows 8.1 on it. I’m wondering if it was a result of upgrading the OS on my old computer, whereas on this one I installed 8.1 fresh…
Ok, I think I found out what it was exactly what sucked up CPU 18%, not dramatic but I like a quiet computer and I don’t see the point of running a CPU for hours in the background. It got to work for me, not for Microsoft. I am the boss, and I normally only have 1% CPU usage.
The svchost.exe runs the Service Host: Local System, on my computer it got PID number 416, I saw that in the vulcan neck pinch – Task Manager – Details.
Then I ran Defender to update it with new virus definitions (this update I have usually blocked), now the same svchost.exe 416 keeps sucking CPU. So I guess it was the Windows Defender all along, scanning my computer for virusses that never have been there because I am such a good boy and can take care of my own.
I am still contemplation to turn that one off. Defender, heave decision, but… Yes I will, don’t need Defender if it runs for hours for nothing, annoying me with the blazing fan. So first I cancel the update, which hasn’t finished yet. I politely wait until it finished installing its current updates. Takes a long time that…. … .. until it finally decides with an alert screen that the update… failed 😉 Ah, darn! the svchost.exe 416 stops at the same time so I can’t try this out now.
Next time the computer starts blazing again I will uinstall Defender. See what happens.
Service Host: Local System, boy it makes my CPU work, for about an hour now, after reboot it starts up again automatically.
At least Microsoft should tell you what it is doing when you click on it in Task Manager. Defragmentation perhaps?
I have Windows update is off by default, Search indexing is off now too. But the Service Host: Local System knows of no stopping. Fan still running at top speed.
Is it stuck in a loop? Does it like it’s loop so bad that it wants to get back to it?
It’s just impolite of Microsoft, the fan is spinning at top speed to cool the CPU because Localhost has to do something. What nobody knows, breaking my computer so I have to buy a new, is that the idea?
I had this same problem all you have to do to make sure it never comes back is to update you computer it does this because it is trying to install an update.
you have to do this because sometimes it will restart and come back and still use cpu
For a permanent Solution Disabling the windows update Worked for me!
To do this you have to right click on the computer,select manage.Next,go to the application and services tab,choose services.There you need to scroll down through the list,it’ll be labelled as ‘Windows Update’.Right click on it and go to properties.Once you are there you’ll see a box in the middle that says manual,change it to disabled and click apply,then click ok.That’ll fix the high cpu and ram usage.Took me awhile to figure that out too!
Thank You!!…It was driving me crazy…It worked for me!
Thanks a lot for the easy discreption! It works very well and my computer is much faster.
tnx so much, it is complitley helpful, :*
Thanks for the guide. It helped me to sort out the problem in my laptop. The steps are simple and clear.
you, good sir, are a gentleman and a scholar 🙂
Thanks a bunch!
Hi, thank… This helped
Windows 8 is definitely consuming your resources running drm, various policing softwares, and sending private encrypted information about you. Since you bought your computer and it is your property and not microsoft’s, this is theft of personal property and resources as well as violating many privacy laws. Unfortunately, microscoft and apparently some people in our government (NSA) are complicit with theft of personal property and violation of privacy law and our constitution as well. The best solution is to call your Congressman and activism. Computer fixes are pointless nearly.
hi people, i hope so you can help me, i have same problem like other guy but only this service using to much my CPU, I try to stop it but then my internet stop work, but after 1 minute come back online, im gona crazy out, i try to stop SuperFetch, i don’t see difference yet, please if have any advice…..
Man! Thanks! You are simply hilarious!!! 🙂 Love the way you explained that. — having the same issue and cannot believe that we still have this thing going on… and everybody has they’re own “solution” to resolve it! SuperFetch, ServiceHost, HardDiskDying, GottaLoveToStruggleWithWin8 and so on!!! Well…guess we wont be speaking about it anymore in another 10 years from now..
Thanks for that laugh.
Of course we will! You mean you don’t talk about the DOS days any more? The thrill of chkdsk, undelete … and how often you resorted to formatting c:? 😀
I was suffering from the same issue which took me some time to figure out finally. I tried all the tips suggested here and other websites as well on the same issue. Nothing worked for me. Did all the undo procedures backward to keep them default setting now. But fortunately I found what was causing all the disturbance. It was Windows Defender. I never had this problems until recently I uninstalled Avira Pro for a test purpose and thought I would be happy with the Windows Defender as a substitute. Well, Windows Defender might be as good as protecting a PC to those commercial antivirus software with addition sucking up the CPU resources to very annoying level. Now, my problem seems to be resolved. Try this please if you have any alternative of Windows Defender.
I currently having high CPU ussage problems too with my Boss’s Asus running 8.1/ But he has two other Asus laptops running 8.1 that are running fine. All of them have Defender on. This is weird! I guess I will try uninstalling Defender on the one running slow and see what happens. Buy the way a brand new Samsung SSD that I cloned does seem to help speed but CPU is still being used way too high.
I had same problem, and i found out by closing sub processes one by one that the culprit is the one called ‘Spot Verifier’ which is the system process for verifying file system corruption and it was running because of bad sectors in my dying HDD. So don’t ignore it, repair your drives from property-> tools and even check health of your hdd with and third party software.
THANK YOU! This problem was driving me nuts.
Another Canadian 🙂
Search “Services” and click on the “View local services” Then you need to find a service called “SuperFetch” and right click on it. Click “Properties” Then you need to click on the little drop down probably labled “Automatic” should be aroung the middle.
Change it to “Manual” and press “Ok” Now you need to right click on “SuperFetch” and press “Stop” That should calm down Svchost.
Many thanks! I recently had to reformat and hadn’t yet disabled SuperFetch (which was certainly sucking up my hard drive resources, but not so much the CPU).
The issue mentioned in the above article eventually went away by itself about a month after I posted this.
Oh, Winderz! 😉
Your recommendations didn’t work with my system. I just had success in stopping the 99% CPU activity by simply setting back the power options to standard.
My 100% CPU usage was fixed by your recommendation. Switching the power options back to “recommended” worked like a charm.
Try opening a lot of apps and enable all services that are disabled
Thanks for your awesome advice! I don’t have very much knowledge on computers, but I was able to follow your direction pretty easily and resolved my own issue. Thanks
Many thanks. it works with me too.
or find ‘system’ in task manager, right click it then select end task