Common Log (CLFS) Service Defaults in Windows 10

General-purpose logging service.

Default Settings

Startup type:Boot
Display name:Common Log (CLFS)
Service name:CLFS
Service type:kernel
Error control:critical
Group:Filter
Path:%SystemRoot%\System32\drivers\CLFS.sys
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\CLFS

Default Behavior

Common Log (CLFS) is a kernel device driver. In Windows 10 it is starting by the operating system Boot Loader as a part of the driver stack for the boot volume. If Common Log (CLFS) fails to load or initialize, Windows 10 attempts to record the error details into Event Log and restart the PC, using the Last Known Good configuration. If the Last Known Good configuration cannot be applied or working improperly, Windows 10 startup process halts with a Stop error. If you disable or delete the CLFS service, Windows 10 won't start.

Restore Default Startup Configuration for Common Log (CLFS)

1. Select your Windows 10 edition and release, and then click Download.

2. Save the Win10_CLFS_Service_Startup.cmd file to a local storage device.

3. Run the saved file as an administrator.

4. Restart the computer.

The CLFS service is using the CLFS.sys file that is located in the %WinDir%\System32\drivers folder. If the file is changed, damaged or deleted, you can restore its original version from Windows 10 installation media.