This policy setting will automatically log off a user when Windows cannot load their profile.
If Windows cannot access the user profile folder or the profile contains errors that prevent it from loading, Windows logs on the user with a temporary profile. This policy setting allows the administrator to disable this behavior, preventing Windows from loggin on the user with a temporary profile.
If you enable this policy setting, Windows will not log on a user with a temporary profile. Windows logs the user off if their profile cannot be loaded.
If you disable this policy setting or do not configure it, Windows logs on the user with a temporary profile when Windows cannot load their user profile.
Also, see the "Delete cached copies of roaming profiles" policy setting.