How to Fix Service Host Superfetch High Disk Usage in Windows

What Is Service Host Superfetch?

Service Host Superfetch (SysMain) is a Windows service that preloads frequently used applications into memory to reduce loading times.

By learning and analyzing your usage habits, SysMain loads data into memory and makes the system more responsive. However, this continuous caching will lead to high disk usage of SysMain in the system and a significant speed decline.

To troubleshoot this issue, you can disable the SysMain service, clear cached data, close running programs, run SFC, and update the system. Check the steps below.

How to Stop SysMain from Hogging Disk Space?

Fix 1. Disable Service Host Superfetch

Disabling SysMain should be the simplest way to resolve the high disk usage issue.

Before doing that, you may wonder whether you should disable Superfetch and what the consequences. As a matter of fact, this operation won’t cause your system instability or glitch. The only drawback is that some delays crop up when accessing commonly used software.

To complete this operation, you can use Windows Services, Command Prompt, or Registry Editor.

The following are the respective steps:

① via Windows Services

Step 1. Press Win + R to bring up the Run dialog box.

Step 2. Type services.msc and hit Enter to open the Service console.

Step 3. Scroll down to find the SysMain service > double-click on it.

Step 4. In SysMain Properties, click the drop-down menu for Startup type > select Disabled > hit the Stop button.

Step 5. Then hit OK to save the changes,

② via Command Prompt

Step 1. Type cmd in the search bar and select Run as administrator.

Step 2. In Command Prompt, copy & paste the command below and then press Enter.

sc stop “SysMain” & sc config “SysMain” start=disabled

③ via Registry Editor

Step 1. Open the Run window (Win + R) > input regedit > hit Enter to open the Registry Editor.

Step 2. Follow the path below to find the SysMain service.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SysMain

Step 3. Select SysMain and look for the Start entry in the right pane.

Step 4. Double-click on it > change Value data to 4 > hit OK to save the change.

You can choose the option that works for you or that you’re comfortable using.

Fix 2. Try MiniTool System Booster

High disk usage from Service Host Superfetch may cause your PC to run extremely slowly. In this case, you can resort to third-party PC tune-up software like MiniTool System Booster to fix the issue and make your PC run faster.

The main functions of this free utility are to find and repair system issues, clean up browsing data, speed up CPU, RAM, and hard drive resources, and more. It can also perform real-time monitoring and fix-up, optimize Windows startup programs, and end memory-intensive background tasks.

You can enjoy all of MiniTool System Booster’s features for free within 15 days. Now, let’s try and check how it works.

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Step 1. Open the program and expand the Performance Home menu to choose Deepclean.

Step 2. Hit START CLEAN to start a series of tasks on your system.

Among the seven cleanup tasks, the Internet Cleanup and Windows Cleanup tasks can help you clear Windows cache, internet junk files, browsing data, etc.

And the Program Accelerator task can boost file access speed and increase drive efficiency by realigning program data and defragmenting files on the hard drive.

After that, you can continue or just skip the rest of the cleanup tasks as per your needs.

Step 3. Then switch to Toolbox. Choose Process Scanner under System Management and click on Scan now. A list of running background processes will be displayed.

Step 4. Click Terminate Process to end the unnecessary processes.

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Fix 3. Perform SFC Scan

If the SysMain high disk usage issue persists after turning it off, you can try using System File Checker. It can check the system files’ integrity and repair the issues found.

Take the following steps:

Step 1. Open Command Prompt as an administrator.

Step 2. In the command window, type sfc /scannow and hit Enter to run it.

Then it will automatically scan your hard disk for corrupted system files and replace them. When finishing, reboot your device and see if the SysMain service is still eating up disk space in Task Manager.

Fix 4. Update Windows

You should check if your Windows is up-to-date since updates contain fixes and patches for system issues, sometimes.

To do that:

Step 1. Press Win + I to launch Settings > head to Update & Security > Windows Update.

Step 2. Hit Check for updates and download & install available ones.

Bottom Line

In summary, Service Host Superfetch is a type of a legitimate Windows service. If you find SysMain in Task Manager showing high disk usage, the 4 solutions mentioned in this guide can keep your Windows free from Service Host Superfetch high disk utilization. Don’t hesitate to give them a try.

Service Host Superfetch High Disk Usage FAQ