Fix: Service Host SysMain high disk usage in Windows 10 & 11

by Tashreef Shareef
Tashreef Shareef
Tashreef Shareef
Windows & Software Expert
Tashreef Shareef is a software developer turned tech writer. He discovered his interest in technology after reading a tech magazine accidentally. Now he writes about everything tech from... read more
Affiliate Disclosure
  • If Service Host SysMain has high disk usage, be sure to install the latest Windows Updates.
  • Certain services can cause performance issues such as this one, so it's advised to disable them.
  • Faulty hardware might also be responsible for high disk usage, therefore you should check it for problems right away.

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If your computer suddenly shows performance issues and starts working slow, it is most likely that a process is causing high disk usage.

Several users have reported Service Host SysMain causing high disk usage issues in Windows 10 and 11, and this can be a problem since it will negatively impact your performance.

In this article, we’ll explore a few troubleshooting steps to help you resolve the issues that you might have with this service, so let’s get started.

What is Service Host Sysmain?

Service Host SysMain (earlier known as Superfetch) is a bundle of system processes. You are most likely wondering how it actually works.

This processes package is supposed to optimize the apps launching and speed up their starting but sometimes it can do quite the opposite, causing high disk and CPU usage.

What causes SysMain high disk usage?

Have you ever wondered why is Service Host Sysmain causing high disk usage? Missing updates are the most common cause for this problem, so it’s advised to keep your PC up to date in order to avoid such issues.

In addition, if this service is causing problems, you might want to try disabling it. Other Sysmain issues include:

  • 100% disk usage
  • High disk activity
  • High CPU usage

How can I stop Service host SysMain from using all disk on Windows 10 & 11?

1. Stop SysMain service

  1. Press the Windows key + R.
  2. Type services.msc and press Enter.
  3. In the Services window, locate SysMain and double click it.
  4. Click the Stop button.
  5. Click OK to save the changes.

Open the Task Manager and check the disk usage to see if it is normal. Stopping the SysMain services from Services can help you resolve the high disk usage caused by the process.

2. Use the Command Prompt

  1. Press the Windows key + S.
  2. Type cmd. Click on Run as administrator to open the Command Prompt.
  3. In the Command Prompt window, type the following command and hit Enter:
    sc stop "SysMain" & sc config "SysMain" start=disabled
  4. You should see Change Service Config Success.

3. Use the Registry Editor

  1. Press the Windows key + R. Type regedit and click OK.
  2. In Registry Editor, navigate to the following location:
  3. You can copy-paste the above path in Registry Editor to navigate quickly.
  4. In the right pane, double-click on Start.
  5. Enter 4 in the Value Data field. Click OK to save the changes.

Close the Registry Editor and then launch the Task Manager and look for Service Host Sysmain. Check if the high disk usage issue is resolved.

4. Check your hard drive

If your Windows computer has a traditional mechanical hard drive, consider upgrading to an SSD. Having your Windows installation and other frequently accessed programs in an SSD makes a lot of difference.

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Most of the modern laptops come with an M.2 slot to install NVMe SSD. If not, you can buy a separate caddy to install the SSD on your old laptop.

For more information, visit our best 250GB and 500GB SSDs guide to find some reliable drive options for your PC or laptop.

The Sysmain 100% disk usage issue usually occurs when the essential system processes run in the background. However, having an SSD will significantly reduce the chances of this issuse occuring.

5. Update Windows

  1. Press Windows key + I to open the Settings app.
  2. Go to Update & Security.
  3. Check for pending Windows updates and install them.

Installing the Windows updates can fix the high disk usage issue caused by a glitch in the operating system.

How can I stop Service host SysMain from using all disk on Windows 11?

Disable the Background Intelligent Transfer Service

  1. Press Windows key + S, type services.msc, and press Enter.
  2. Locate and double-click on Background Intelligent Transfer Service.
  3. Now click on Stop and save changes.

Can I end Service Host Sysmain?

If you’re having performance issues on your PC, including slowdowns, it’s advised to disable this service in order to improve performance.

Disabling it won’t cause any additional problems, but it’s not recommended to do so unless you’re having issues with the service.

What causes high disk usage on my PC?

Disk usage lockups in Windows 10 is caused by third-party applications, such as your antivirus, and if antivirus is performing a full system scan, it’s normal to expeirence this issue.

In addition to third-party apps, certain storage-related services can negatively affect your overall performance. Various services can also cause this issue and Windows host process rundll32 is known for disk problems.

If the SysMain is causing high disk usage in Windows 10 and 11, this can make your computer slow affecting the performance of other programs.

In case you’re having additional problems, visit our 100% disk usage guide on Windows to see how to properly fix this issue.

Did you find a solution to this problem on your own? If so, feel free to share your solution with us in the comments section below.

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