When installing Mac OS 9 by starting up from the Mac OS 9 CD, some hard disks behave as if they are damaged and unreadable, when in fact they are not. This article describes the exact symptom and offers the solution.

When starting up from the Mac OS 9 Installation CD (by pressing the 'c' key during startup), a dialog box may appear stating that the computer's hard disk is unrecognizable and asks if you would like to initialize (erase) it.

Solution

Apple has identified an issue with a limited number of hard disks that result in this message when starting up from the Mac OS 9 CD. The files and directory structure on these drives are not modified or damaged in any way. To resolve the situation:

1. Click Cancel in the dialog box.

2. Restart from hard disk, making sure the Mac OS 9 CD is still in the computer.

3. Open the Startup Disk control panel and select the Mac OS 9 disc. See Figure 1.

4. Close the Startup Disk control panel.

5. Restart the computer from CD, and proceed with the Mac OS 9 installation.

Figure 1 Startup Disk control panel showing Mac OS 9 CD selected as startup disk.