A process called Service Host: Local System is using up all of my laptops resources

Changing my "check for windows updates" to "never" worked! Now I just have to figure out why checking for updates was using up so much CPU. 

This problem has been annoying me for some months and having tried the different hints elsewhere on the thread and not wanting to change the Windows Updates to Never, I finally was motivated to do some detective work. Turns out, for me at least, the process “Service Host: Local System : Windows Update” is the culprit but I don't know why it does it.

In my case after rebooting PC all would be OK for a while but then, for no apparent reason, the CPU load would be high and fan would continuously run. So I tracked down the culprit with the following steps:

1. Reboot the PC.
2. Start Task Manager and select the Processes Tab.
3. Sort by CPU (normally you should only see Service Host: Local System intermittently at the top of the list as it consumes less than 1% CPU on my machine).
4. Locate the Service Host: Local System (sort on Process Name and go to the Windows Processes section).
5. Expand the Process to show all the sub processes.
6. Take a screen shot and save it somewhere to capture the processes (I dropped the screen shot into a Word Document)

Whenever I noticed that the CPU load was unusually high and the cooling fan running continuously I popped up Task Manager and repeated steps 1 to 6 above. Then compared the new screen shot against the reference screen shot under normal operating conditions.

Among the new processes listed were Multimedia Class Scheduler, Group Policy Client and Windows Update. Windows Update appealed to me as an easy target,  so I took a chance and stopped the process (right click on the process name and select Stop) and bingo the CPU load immediate falls back to normal.

I've repeated this procedure several times with no apparent side effects. I guess the Windows Update should start, check for updates, then stop again. But it is obviously not stopping correctly.

Obviously you need to be careful about stopping processes this way as it could render the system unstable. 

Hope this helps.

Ian,

Thanks for the help. I don't like doing much digging down to solve problems, but i'm fed up with this one. In control panel there is no way to disable Windows update (outside of upgrading to professional), but this web site

https://www.cnet.com/uk/how-to/stop-windows-10-from-automatically-updating-your-pc/ 

Gives a partial solution that I'm going to run with for now.

My laptop has been running very slowly for the past few days which is weird because my laptop is quite powerful and has always run very fast. I looked at my task manager and saw that a process called Service Host: Local System was using up almost all of my RAM. I am running Windows 8 Pro on a Sony VAIO S13P. What can I do to fix this problem?

If your on Windows 10 go Windows update, your computer is most likely downloading an update and getting ready to install. Windows 10 automatically does this. It can slow Cpu, networking, memory, and disk. Get the updates done and you will be fine (until they roll out more updates)

So i was playing GMod and it was lagging and so i check task manager and service host was taking a whole lot of cpu away (just cpu) so i changed windows update to never. but it was still taking so much cpu so i stopped the service and the cpu usage went WAY down :P

now i have that service temporarily disabled xD

I had this same issue and a Microsoft support technician completed the following steps and wrote this tutorial for me when I requested it.  Now, instead of the Service Host: Local System using over 90% of my disk space, it only uses a little over 20%:

How to clear system junk files

step 1: please press windows key + r key at the same time to open run command, In run command window type temp then press enter key. You may see temp folder

step 2: In temp folder please press ctrl+a key at the same time to select all the files, then press delete key. It will delete all the files and store it in recylce bin

step 3: Then open run command using the first step, then type %temp% and press enter key. In %temp% folder delete all the files, some files cannot be deleted. please skip those files alone

step 4: Then again open run command using the first step, then type prefetch and press enter key. In prefetch folder delete all the files

step 5: Now select recycle bin and right click in that remove/clear files from recycle bin. These will remove the system junk files

To impove system performance

step 1: please open run command, in that type msconfig then press enter key. You may see system configuration window

step 2: In that window select boot tab, then select advanced options. In advanced options window click the check box under number of processor and maximum memory. please use the drop-down to set maximum or full performance in your PC

step 3: then click ok, after that please click apply and ok. You may see a pop up to make the changes more effective restart will appear, please click restart to enable full performance in your PC

all in one support link: Free Microsoft support link for all products

https://support.microsoft.com/en-us/contactus/windows/