Note: You are currently viewing documentation for Moodle 2.3. Up-to-date documentation for the latest stable version is available here: Journal module.
The Journal Module has been disabled during install by default since Moodle 1.5 (when all Journals were converted to Online Assignments)
In order to avoid data loss, the installation of the journal plugin on a Moodle 2.0 should follow the Upgrading to Moodle 2.0 guidelines. That discussion about the best way to upgrade contrib plugins to Moodle 2.0 could also be useful.