SysMain Service Defaults in Windows 11

Maintains and improves system performance over time.

Default Settings

Startup type: Automatic
Display name:SysMain
Service name:SysMain
Service type:share
Error control:ignore
Group:profsvc_group
Object:LocalSystem
Path:%SystemRoot%\system32\svchost.exe -k LocalSystemNetworkRestricted -p
File:%SystemRoot%\system32\sysmain.dll
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SysMain
Privileges:
  • SeTcbPrivilege
  • SeProfileSingleProcessPrivilege
  • SeTakeOwnershipPrivilege
  • SeDebugPrivilege
  • SeIncreaseBasePriorityPrivilege
  • SeLockMemoryPrivilege
  • SeCreateGlobalPrivilege

Default Behavior

SysMain is a Win32 service. In Windows 11 it starts automatically during the operating system startup. Then the SysMain service logs on as LocalSystem and running in a shared process of svchost.exe. If SysMain fails to load or initialize, Windows 11 is starting up without warnings, however the error details are being logged.

Dependencies

SysMain cannot be started, if the following services won't start:

Restore Default Startup Configuration of SysMain

Before you begin doing this, make sure that all the services on which SysMain 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 C:\Windows\system32 directory. If the file is removed or corrupted, read this article to restore its original version from Windows 11 installation media.