How to Disable Superfetch (Sysmain) in Windows 11

Patrick_Yu

Windows 11 is built for speed and efficiency, but not every background service helps every user. One service that often comes up in performance discussions is Superfetch, now known as SysMain. While it’s designed to improve performance on most systems, some users find it causes high disk or CPU usage instead. If you're one of them, disabling Superfetch could be a helpful tweak.

This guide covers:

• What Superfetch is and what it does
• Whether it’s safe to disable Superfetch
• How to disable it using the terminal (Command Prompt or PowerShell)
• How to disable it via the Services Manager

What is Superfetch and what does it do?

Superfetch, renamed SysMain in newer versions of Windows, is a Windows background service that analyzes your usage patterns over time and preloads frequently used apps into memory. The idea is to make programs launch faster by having them partially loaded into RAM before you even open them.

Key functions of Superfetch/SysMain:

• Preloads commonly used applications into memory
• Improves boot times over time by optimizing startup processes
• Continues to run in the background to adjust preloading based on changing user behavior

While this can be helpful on systems with abundant RAM, it may become problematic on lower-end machines or those using slower storage, such as HDDs. Many users report high disk usage caused by SysMain, especially immediately after boot-up.

Is it safe to disable Superfetch?

Yes, it is safe to disable Superfetch (SysMain)—especially if you're experiencing high disk or CPU usage. Disabling it won’t harm your system or cause instability. However, you might notice:

• Slightly slower launch times for frequently used apps
• A marginally slower boot time, especially if your system previously benefited from SysMain's optimizations

If your PC has a modern SSD and plenty of RAM, you’re unlikely to notice any negative impact from disabling it.

How to disable Superfetch (SysMain)

You can disable Superfetch in two ways:

1. Disable Superfetch via the terminal

You can use either Command Prompt or PowerShell for this method.

Step-by-step:

1. Press Windows + S, type PowerShell, then right-click and choose Run as administrator.
2. To stop the service immediately, enter: Stop-Service -Name "SysMain" -Force
3. To prevent it from starting again on reboot, run: Set-Service -Name "SysMain" -StartupType Disabled

This stops SysMain instantly and disables it from starting automatically in the future.

2. Disable Superfetch via Services Manager

If you prefer a graphical interface:

Step-by-step:

1. Press Windows + R to open the Run dialog
2. Type services.msc and press Enter
3. In the Services window, scroll down and find SysMain
4. Right-click SysMain and select Properties
5. In the Startup type dropdown, select Disabled
6. Click Stop to halt the service immediately
7. Click Apply, then OK

This method is especially useful if you want to re-enable the service later without using the terminal.

How to enable Superfetch (SysMain)

If you want to turn Superfetch back on later, you can easily re-enable it using the same tools.

1. Enable Superfetch via the terminal

Steps:

1. Open PowerShell or Command Prompt as Administrator
2. Set the service to start automatically: Set-Service -Name "SysMain" -StartupType Automatic
3. Then start the service immediately: Start-Service -Name "SysMain"

SysMain will now run and load at startup like before.

2. Enable Superfetch via Services Manager

Steps:f

1. Press Windows + R, type services.msc, and press Enter
2. Locate and double-click SysMain
3. Set Startup type to Automatic
4. Click Start to launch the service
5. Click Apply, then OK

This reactivates the service and allows it to run normally.

Final thoughts

Superfetch (SysMain) is a legacy performance optimization tool designed to improve app responsiveness over time. But on some systems, especially those with older hardware, it can cause more harm than good. If you’re dealing with persistent disk usage issues or system slowdowns after startup, disabling SysMain is a safe and effective troubleshooting step.

With both command-line and graphical instructions provided, you now have everything you need to take control of SysMain on your Windows 11 PC.