Install Wizard showing again after installation succesful

After installing Piwik in an IIS 6 server after a successful installation I the installation wizard is showing again…
How can I solve this?

Check if the config.ini.php (piwik/config) has been successfully created. If not, edit and rename the config.ini.sample.php.

The most likely cause is Windows ACLs prevent PHP from creating config/config.ini.php

Thanks that was exactly the problem!
It will be nice if the Wizard detected the permissions problems to show a warning thou
Thxs again!