Source of 100% disk usage?

Hello,

I would greatly appreciate any help you might offer solving a recent problem with my computer. Over the past few days my disk usage has been run up to 100% and I cannot seem to fix it. It is causing very significant performance issues in an otherwise brand-new computer purchased about three weeks ago.
Specs:
Dell Inspiron 17
Intel Core i7-7500U @2.70 GHz
16.0 GB RAM
NVIDIA GeForce 940MX
WebRoot SecureAnywhere antivirus

Two days ago I was browsing the internet and installing/uninstalling several media management programs (aTube catcher, MediaMonkey). My system began to run very slowly, so I closed all programs one by one and restarted the computer. I was stuck at the "Getting Windows ready - do not turn off your computer." screen for about an hour before the computer actually started again. I checked the task manager to see if the performance had been fixed, and found disk usage to be sitting at 99%, with other parameters normal. I suspect culprit has to be somewhere in the "Service Host: Local System" or "System" processes, as they are the first to jump to the top of the list in terms of disk use. (See attachments)
Since then, I have done the following:

• Disabled the "Background Intelligent Transfer Service (BITS)" and "Superfetch" services, turned off most Windows sharing options. I searched for initial solutions to this problem and the method of disabling these kept coming up. I also changed both of these options' values in the registry editor to keep them from activating themselves, but they appear to still be running. (See attachments) This initially brought me back down to regular disk usage percentages, but as of this morning I have returned to 99%.
• Ran full system scans with avast! antivirus, including a boot-time scan. Created an avast! restore on a flash drive.
• Checked that Windows and all drivers are up to date.
• Disabled non-critical startup programs that were slowing down the computer. (See attachments)
• Uninstalled "crapware" (Bonjour, a Steam game, etc.)
• Created a restore point for the system when it appeared to have returned to regular percentages. I would go back to this point, but nothing has changed with my system since creating it and I still ended up at 99%. If I had to do a total system restore to factory condition I would not be set back too far, but I would like to avoid it if possible.
• Uninstalled avast! Free antivirus assuming it was conflicting with WebRoot and draining resources. No result. I've used avast! for years without much issue but the free WebRoot subscription that came with this computer was touted as being very lightweight. Does not appear to have helped.

I have been very safe in terms of browsing since getting this computer and would like to restore the speed to what it was. If the problem is in the processes (BITS and/or Superfetch), perhaps I can resolve the issue by getting the values in the registry editor to stay at 0, disabling them.

Please let me know any thoughts or methods you might have in resolving this, and thank you very much for your time!

Hello TairikuOkami,

Thank you for getting back to me. I just want to be sure I have these selections right before going through with installation so I don't worsen the problem. Please let me know if the below is correct:

I had this issue and disabling Superfetch and Windows Search services fixed it for me. I still see 99% usage at startup, but is usually comes down after two to three minutes.

TairikuOkami, I have installed and am now using the Home+ Pro version. It seems like the Creators update is also running. Disk usage is down a little and watching it on the task manager causes it to rise up to a little over 60%. This now seems to point out a few specific processes (Superfetch?) that could be causing the slowdown. Where should I go from here?

tracit99, I agree with disabling those two. It did help after the first restart, but for whatever reason what I entered into the registry editor was keeping them from staying disabled. I will likely have to re-disable them with this new installation. How did you keep your settings from reactivating themselves?

The way I do this is to go to Control Panel>Administrative Tools>Computer Management>Services and applications>Services and set Superfetch and Windows Search to disabled. They should remain disabled even after restart.

Assuming those are to be input into the command prompt, the following appears:

For "sc config SysMain start= disabled": [SC] OpenService FAILED 5: Access is denied.
For "net stop SysMain /y": System error 5 has occurred. Access is denied.

I disabled and stopped Superfetch in Services and tried the commands again. "sc config SysMain start=disabled" gets me the same error, but "net stop SysMain /y" now gives: The Superfetch service is not started. More help is available by typing NET HELPMSG 3521.
I'm assuming that there's still nothing to stop Superfetch from turning itself back on at startup, what should I do now?

Edit: I'll check on the status of Superfetch, BTI and Windows Search after an update and see what %'s I am averaging.