I guess, the setting of session.save_path is not correct for you.
It's in your php.ini files, probably in your windows directory.
See here:
http://ez.no/developer/ez_publish_3/forum/install_configuration/first_install_access_denied_no_database_connection_failed_to_openwrite_file (read the 2nd post for a solution)
It also could be a problem with your Database settings (see here: http://ez.no/developer/ez_publish_3/documentation/installation_and_configuration/troubleshooting/warning_failed_to_write_session_data_user_)
For more, search the website for "session.save_path"