System errors and program crashes are sometimes caused by corrupted System Software. Simply running Apple's Installer will not always repair damaged system files. Often, the only way to ensure you have brand-new system software is to Clean Install which replaces all of the Apple software in your System Folder with new copies. I recommend doing this as general maintenance every 4-8 months or whenever a machines begins crashing regularly.

The Apple Installer program looks for two things to determine if your computer has a 'blessed' system folder. First it checks to see if there is a folder with the System and Finder files inside. It also checks to see if there is a folder called 'System Folder'. If neither of these conditions are true, the installer creates a new system folder, which is what performing a 'clean install' is all about.

Step 1: Un-bless your system folder

• Rename your System Folder to anything other than 'System Folder'. 'Fred' or 'blah' works (I usually choose 'Old Sys' so I know what it is).
• Move the System file so it is no longer in the same folder as the Finder file (I usually put the System file in the 'Preferences' folder).
• DO NOT restart your computer! You've just disabled (unblessed) your System Folder and your Mac won't boot again until you install new system software.
• If necessary, use the 'Startup Disk' control panel to tell your computer to start up from a CDROM, Zip drive, etc.

Step 2: Run the Installer

• Run Apple's Installer from your CDROM, or System disks that came with your computer.
• Select the name of your hard drive as the disk to install onto.
• Feed the disks as it asks for them or go have a cup of tea if you're installing from a CD. This takes a while.
• Restart your computer when the installation is successful.
• There will be a newly created 'System Folder' on your hard drive with fresh, clean system software inside.

Step 3: Move/reinstall other software

• Inside your old system folder (renamed as in step 1 above) are many other files which may need to be moved to the new System Folder. These files are in the Extensions, Control Panels, Apple Menu Items, Preferences and Startup Items folders to name a few. Every machine is different depending on what you had installed before you clean installed.
• Start by moving any aliases you had in the Apple Menu Items folder of your 'Old Sys' folder to the Apple Menu Items folder in your new 'System Folder'. The idea here is not to replace any of the new, clean files, just move any extra files you had installed. You don't need to move things like Chooser or Find file-they're already there from the clean install. If you get a dialog box asking if you want to replace something, choose 'Cancel'.
• Move third party extensions and control panels from your 'Old Sys' folder to your new System Folder. Again, don't replace any new files with old, possibly corrupted files.
• Extensions and Control Panels load when you restart. I recommend moving a few extensions or control panels at a time and then restart, rather than just dumping all third party software back into your new System Folder. This helps identify a troublesome file before you've moved 25 or more files and don't know which one is still causing a problem.
• Some software actually needs to be reinstalled from the master disks to work properly.
• Many applications store their settings in the Preferences folder. If a program looses some of its configuration, serial number or settings, move the prefs file from the Preferences folder in 'Old Sys' to the Preferences folder in the new System Folder.

Step 4: Reconfigure settings, etc.

• After clean installing you'll need to re-enter your name in the 'Sharing Setup' control panel and possibly reset your memory settings in the Memory control panel. If you've made other adjustments to your settings in other control panels (such as Monitors, or Sound, etc.), you'll probably need to reconfigure those too.

Since everyone's computer is different, it's hard to list every file to move and setting to reconfigure. Moving all these files can be a time consuming process as there can be quite a few on some computers, but this is the best way to keep your Macintosh happy and reduce the frequency of crashes! Good luck!

Kirk van Druten
LANSharks Consulting
510-601-5475 voice
510-601-5130 fax
kirk@lansharks.net
www.lansharks.net