Possible power overload. The Mac found a startup disk, but the disk or software is damaged. The Mac cannot find a startup disk or the system software is damaged . The Mac has found the startup disk, but there is a problem with it . Hard disk does not show up on the desktop.
System software is damaged.
Reinstall the system software. Do not click on OK . The disk information is damaged. Use a disk utility, such as Norton to repair the disk if possible. Disk information is damaged.