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

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/

Signed up so I could join this forum and present my problem too- I have too many 'service host' processes and the 'disk' section of my task manager is running at 90-100% which is not normal for my laptop. I usually run anywhere from 0-30%, sometimes up in 40%.

I had an obvious malware try to install a 'firefox update' on my laptop from a popup website unrelated to mozilla, which I simply closed. Next day when I turned my laptop on I manually closed a firefox update via task manager because I thought it was malware again, so I force closed it just in case, but it turned out to be the real firefox update and now my laptop is running a butt ton of 'service host' programs that are putting my task manager 'disk' in the red and at 90-100%.

As soon as I closed the update it said 'firefox cannot load XPCOM' and wouldn't start so I uninstalled and then reinstalled firefox and then rebooted, but my task manager 'disk' is still in the red. And now instead of listing one or two firefoxes in task manager, like normal, it's listing three. Dunno what to do but I don't want to close something I'm not supposed to again...

I've tried most of the solutions in this thread and none have worked, I assume because this is related to stopping firefox update somehow. I even went to mozilla firefox support forum where I had no luck when I followed the directions someone gave me there (uninstall and full clean reinstall firefox- which didn't work) I've uninstalled and reinstalled firefox several times but I still have all these service host processes.I also tried stopping windows defender and turning off the windows updates to never, tried stopping BITS, and turned off all startup processes.

I also used command prompt and entered 'sfc/scannow' and got this:

I don't know what to do. I've scanned using Advanced System Care 10 and IObit Malware Fighter, just in case there was a virus causing this or something, but no malware came up. The 'service host' processes only appeared after I stopped firefox update as it was downloading. They never appeared before. Thinking I might just wipe my laptop like new and put all my files on usb, but help would be greatly appreciated before I resort to that.

Same problem.  It is using up the most but not all.  Task Manager doesn't show what is running constantly, but I can hear the disk running all the time and everything is slow.

"First of all I would like to say that I'm very disappointed with Microsoft due to their lack of response."

This is because they have outsourced all of the customer

service work outside of the United States!

that command is wrong!! the command:sfc' /scannow'

i get message wrong or incorrect label etc the right one is sfc /scannow