> Which module is capable to do this (SSO), probably you mean the core > capabilities to share user tables ? And how fix the multiple "uid" already > registered on multiple sites by the same users ?
Paolo, 1- As someone said, you should really put this kind of questions to the support list. 2- Google is your friend and so is the search field on Drupal site. 3- The module capable of doing "SSO" is called, not surprisingly, "SSO" and you may find it at http://drupal.org/project/sso 4- Try also this module -- User Import (http://drupal.org/project/user_import) -- to the second part of your question. HTH. Roberto
