Changing user registration settings
From Joomla! Documentation
Set "Allow user registration" to "no" to stop users to create an account for your site themselves.
J1.5:User registration settings are managed in the Global Configuration screen in the Administrator back-end. To change the user registration settings, do this:
- Log in to the Administrator back-end. To learn how to do this read: Logging in or out of the Administrator back-end.
- Click on the Global Configuration button in the main Control Panel or click the Site > Global Configuration menu item.
- There are so many configuration options that they need to be divided into separate groups or tabs. Click on the System tab.
- You should see a group of configuration fields under the title User Settings.
- Change the User Settings fields to suit your requirements.
- Click the Save or Apply toolbar button to implement the new settings:
- The Save toolbar button will save your changes and return you to the Administrator Control Panel.
- The Apply button will save your changes but leave you in Global Configuration.
- You should see a blue message: "The Global Configuration details have been updated." which confirms that your changes have been saved.
- If you see a red error message refer to Cannot save Global Configuration changes.