Disable Simple file Sharing through registry or GPO

Need to turn off the simple file sharing of an XP machine through remote registry or GPO?

HKLM\System\CurrentControlSet\Control\LSA\ForceGuest

Change it from 1 (enabled) to 0.

For GPO navigate to:
Computer Policy-Windows Settings-Security Settings-Local Policies-Security Options and locate Network Access: Sharing and Security Model for Local Accounts and set it to Classic.