UAC File Virtualization (luafv) Service Defaults in Windows 7

Virtualizes file write failures to per-user locations.

Default Settings

Startup type: Automatic
Display name:UAC File Virtualization
Service name:luafv
Service type:filesys
Error control:normal
Group:FSFilter Virtualization
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\luafv

Default Behavior

UAC File Virtualization is a file system driver. In Windows 7 it is starting automatically on the operating system startup. If UAC File Virtualization fails to start, Windows 7 attempts to write the failure details into Event Log. Then Windows 7 startup should proceed and the user should be notified that the luafv service is not running because of the error.


UAC File Virtualization is unable to start, if the FltMgr service is stopped or disabled.

Restore Default Startup Configuration of UAC File Virtualization

Before you begin doing this, make sure that all the services on which UAC File Virtualization 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 luafv start= auto
sc start luafv

3. Close the command window and restart the computer.

The luafv service is using the luafv.sys file that is located in the C:\Windows\system32\drivers directory. If the file is removed or corrupted, read this article to restore its original version from Windows 7 installation media.