Magento provides a configuration option to help you show a demo store notice when your web store is not yet live and you are just running a demo store.

To enable/disable the demo store notice:

1. Log into the Magento Admin

2. Navigate to System >> Configuration

3. Select the Design Section

4. Click to expand the HTML Head block group

5. Select “Yes/No” from the dropdown for “Display Demo Store Notice” to “Show/Hide” the demo store notice. You will find this dropdown at the end of the HTML Head block group.

6. Click the “Save Config” button to save the configuration changes.