How to configure default parental settings for all users (10.7)?

Hello,

I've made a silent installation of iTunes using MSI files and it works well.

I need to enable parental controls and configure it. Users must be preventing of changing these settings.

At the end of the iTunes installation I automatically created registry keys :

[HKEY_LOCAL_MACHINE\SOFTWARE\Apple Computer, Inc.\iTunes\Parental Controls]

"AdminFlags"=dword:001b7ac5

"AdminMoviesLimit"=dword:000000c8

"AdminTVShowsLimit"=dword:000001f4

"AdminRatingSystemID"=dword:0000000b

"AdminGamesLimit"=dword:0000012c

According to http://support.apple.com/kb/HT2102 it is the procedure to set default parental settings for all users and to lock these settings.

When iTunes is first launched, parental settings are not set nor locked.

I use iTunes 64 bits on Windows 7 64 bits.

Where is the mistake?

Thanks in advance.