Symptom
When you insert a disc into the drive an alert box with this message appears:
"This disk is unreadable by this Macintosh. Do you want to initialize the disk?"
Solution
If other discs of the same type seem to work, make sure the disc is clean and free of scratches and debris. See technical document 50448: "Mac OS 9: How to Handle and Clean CD and DVD Discs".
When the optical drive does not recognize a particular type of disc, this usually indicates the CD-ROM software is not properly installed, or is missing certain files. In some cases, one or several CD-ROM "Access" files may be damaged or a third-party extension or control panel may be conflicting with the CD-ROM software. Try the following suggestions to resolve this issue:
Make sure you have not started your Macintosh with the Shift key held down; this disables the CD-ROM extensions and all other extensions. Make sure you have not disabled the CD-ROM extensions using the Extensions Manager or a similar third-party utility.
Make sure that these files are in the Extensions folder of your System Folder:
- Apple CD-ROM or Apple CD/DVD Driver
- Apple Photo Access (if you plan to use Kodak Photo CDs)
- Foreign File Access
- High Sierra File Access (not present in Mac OS 9.1 or later)
- ISO 9660 File Access
- Audio CD Access
- UDF Volume Access (not present prior to Mac OS 8.5)
If any or all of these files are missing, search the hard disk to see if they have been moved to a different location, then move the files back into the Extensions folder. You must restart the computer after moving the files to the Extensions folder for the files to work properly.
If the files listed above have been deleted, reinstall the CD-ROM software from your Macintosh System CD or system disks, depending on which one came with your computer. If you have updated the system software to a newer version, install the CD-ROM software using the system CD or disks for the newer system software.
If you do not have the option to custom install the CD-ROM software from your system CD or disks, it may be available for download.
Alternately, you may also reinstall the entire system software for your computer. This restores the necessary CD-ROM files.
If these files are damaged, drag the CD-ROM files mentioned above to the Trash, empty the Trash, then reinstall the CD-ROM software. Restart and test to see if the disc appears on the desktop.
If the preceding steps fail to resolve your issue, an extension may be conflicting with the CD-ROM software. Open the Extensions Manager control panel and choose "Mac OS Base" from the Sets pop-up menu.
When you restart the computer, only the extensions installed with your system software load. Test your CD-ROM discs to see if they work, then add extensions and control panels back one at a time, restarting after adding each one to isolate which extension is causing the conflict.
Note: If you are using system software earlier than System 7.5, you have to manually drag extensions and control panels out of the System Folder and restart each time to isolate the offending file.
Once you isolate the conflicting extension, contact the software manufacturer or vendor for compatibility information, or disable the extension to resolve the issue.