Superfetch (SysMain) Service Defaults in Windows 10

Maintains and improves system performance over time.

Default Settings

Startup type:Automatic
Display name:Superfetch
Service name:SysMain
Service type:share
Error control:ignore
Path:%SystemRoot%\system32\svchost.exe -k LocalSystemNetworkRestricted -p
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SysMain
  • SeTcbPrivilege
  • SeProfileSingleProcessPrivilege
  • SeTakeOwnershipPrivilege
  • SeDebugPrivilege
  • SeIncreaseBasePriorityPrivilege

Default Behavior

Superfetch is a Win32 service. In Windows 10 it is starting automatically when the operating system starts. Then the Superfetch service is running as LocalSystem in a shared process of svchost.exe along with other services. If Superfetch fails to load or initialize, Windows 10 start up proceeds without warnings. However the error details are being logged.


Superfetch cannot be started under any conditions, if the following services are disabled, deleted or working improperly:

Restore Default Startup Configuration for Superfetch

Before you begin doing this, make sure that all the services on which Superfetch depends are configured by default and function properly. See the list of dependencies above.

1. Run the Command Prompt as an administrator.

2. Copy the commands below, paste them into the command window and press ENTER:

sc config SysMain start= auto
sc start SysMain

3. Close the command window and restart the computer.

The SysMain service is using the sysmain.dll file that is located in the %WinDir%\system32 folder. If the file is changed, damaged or deleted, you can restore its original version from Windows 10 installation media.