Using Mac OS 9's Multiple Users feature you can have a password at startup. If you need very strong security, or are not running Mac OS 9 you may need to purchase a third-party solution such as a screen saver, or other security software.
The Password Security control panel is not compatible with certain Macintosh computers, including:
- Desktop Macintosh computers such as the iMac or Power Macintosh G3.
- iBook