Errore Installazione Joomla 1.5

Salve . Ho un problema con l'installazione di Joomla.
Dopo aver installato correttamente joomla clicco sul bottone dell'amministrazione e ricevo il seguente errore:

Notice: ini_set() has been disabled for security reasons in /membri/wiitalianspace/libraries/joomla/session/session.php on line 102

Notice: ini_set() has been disabled for security reasons in /membri/wiitalianspace/libraries/joomla/session/session.php on line 105

Notice: ini_set() has been disabled for security reasons in /membri/wiitalianspace/libraries/joomla/session/session.php on line 682

Warning: render() [function.render]: Unable to access /membri/wiitalianspace/installation/installer/installer.php in /membri/wiitalianspace/installation/includes/application.php on line 83

Warning: render(/membri/wiitalianspace/installation/installer/installer.php) [function.render]: failed to open stream: No such file or directory in /membri/wiitalianspace/installation/includes/application.php on line 83

Fatal error: render() [function.require]: Failed opening required '/membri/wiitalianspace/installation/installer/installer.php' (include_path='.:') in /membri/wiitalianspace/installation/includes/application.php on line 83