These instructions call for you to test for the issue at regular intervals. To test for an issue, repeat the actions you took just before you saw the issue on your computer.
An easily reproducible issue facilitates testing (for example, if your screen freezes whenever you insert a floppy disk). However, you can also use this procedure to troubleshoot intermittent issues -- it will simply take longer to test for them.
What's an INIT?
System files that contain INIT resources are collectively referred to as INITs. The purpose of an INIT resource is to load into random access memory (RAM) at startup time and modify the standard behavior or add new features to the Macintosh operating system.
System extensions, control panels (cdevs) and Chooser extensions (rdevs) may contain an INIT resource. Control panels differ from system and Chooser extensions in that a control panel has a user interface where you can modify the parameters. System and Chooser extensions have no user interface to modify parameters.
In general, the term extension is used interchangeably with INIT, and refers to any of those files that contain an INIT resource. For more information about system files and what they do, read the Tech Info Library article "Macintosh System Folder: Files Described."
Troubleshooting Procedure
Follow these instructions in the order presented.
Turn Off Some Control Panel Settings
Turn off some of the control panel settings to check application compatibility with certain features first implemented in System 7.
1. Open the Memory control panel, click on Use Defaults, and restart your computer. This will turn off virtual memory and 32-bit addressing, and reset the disk cache to its default settings.
2. Turn off file sharing in the Sharing Setup control panel.
3. Test for the issue with these features turned off.
Some older applications may be incompatible with these features. So if this resolves the issue, contact the application vendor.
Disable Extensions
Note: In cases where it isn't feasible to disable ALL extensions (for example, if you're having issues launching an application that requires the QuickTime extension) skip to the Isolating Extensions section.
Verify that the issue is related to extensions, following these steps:
1. Make sure the Caps Lock key is off, and restart your Macintosh.
2. After you see the smiling Macintosh, hold down the Shift key.
3. If you are using System 7.5 or newer, hold down the Spacebar until the Extension Manager appears on screen. Select "System 7.5 Only" (or whatever is appropriate for your version of the Mac OS) from the Sets menu. This will load only those extensions installed during your original system software installation.
4. Release the Shift key when the "Welcome to Macintosh, Extensions Off" message appears.
5. When the Macintosh is ready, try to recreate the erratic behavior.
If the issue no longer occurs, then you have an Extension conflict.
Continue with the next section.
Identify the Conflicting Extension
1. Create a new folder on the desktop called "Removed Extensions."
2. Move all items of Kind "system extension," "control panel," or "Chooser extension" from the System Folder, Extensions folder, and Control Panels folder to this new folder. When you open these folders, choose "by Kind" from the View menu to help identify the files you need to move.
3. Close the System Folder, and restart the Macintosh. Test for the issue. Note: If the issue still occurs, check your System Folder to make sure you've removed all the extensions and control panels.
4. Move one item from the new folder on the desktop to the closed System Folder and restart the Macintosh.
5. Attempt to recreate the original issue.
Repeat steps 4 and 5 for each item in the Removed Extensions folder until the issue recurs. The last item returned to the System Folder is likely to bo be the cause of the issue.
Install the Compatible Version
Contact the extension developer for compatibility information. If you have the compatible version, reinstall it from the original disk or from your backup.
If you still have issues with an extension which should be compatible, follow the instructions for isolating this extension from the others on your system.
Isolating Extensions
Follow the steps in this section when you need to test a single extension in isolation. For example, if you just installed the Macintosh PC Exchange control panel, and it doesn't work properly, the cause may be a conflict with another extension.
Make sure you have a startup floppy disk available (that is, a floppy disk containing a System Folder and enabler if required). You can use the Disk Tools disk.
1. Open the hard disk icon and create a new folder called "Test Folder."
2. From the root level of the System Folder, drag the System and Finder files to the Test Folder. Also move any files called System Enabler followed by a 3-digit number, from the root level of your System Folder to the Test Folder.
3. Drag the extension or control panel you wish to test in isolation to the Test Folder as well.
4. Restart the Macintosh. Note: If you experience issues starting up, restart with the startup floppy disk, and make sure you've moved the correct files to the Test Folder.
5. Test for the issue.
6. If the issue recurs, you may have an incompatible extension, or some damage to the System file. Check the compatibility and reinstall the extension and the system software if necessary.
7. If the issue doesn't recur, there's some incompatibility between extensions. Drag the System, Finder, System Enabler (if any), and the extension you're testing back to the System Folder.
Note: Don't drag any of the folders you may see in the Test Folder back to your System Folder. The system automatically creates these empty folders.
Follow the instructions in the "Identify Conflicting INIT" section, with this important exception -- remove all system extensions and control panels from the System Folder except the one you're testing. Begin with this extension in place, and add the others one at a time until the issue recurs.
If after following all the above procedures and the issue continues, it is recommended that a clean system software install be performed.