Before you begin the installation, do the following:

•	Turn off virus-protection and disk-security software.
•	Turn off At Ease software.
•	If you have a portable computer, plug it into a power outlet and set it so it doesn't go to sleep. Turn off password protection in the Password Security control panel.

IMPORTANT: It is highly recommended that you back up the data on your hard disk before installing system software.

To reinstall system software:

1	Start up from the Mac OS 9 software install CD.
2	Double-click the Mac OS Installer icon.
	Depending on how you received your system software, this icon may be labeled Mac OS Install, or it may be named after your computer.
3	Follow the onscreen instructions.

Adding or removing system software components

You can add or remove specific components of the system software by performing a custom installation and removal.

To perform a custom installation and removal:

1	Start up from the Mac OS 9 software install CD.
2	Double-click the Mac OS Installer icon.
	Depending on how you received your system software, this icon may be labeled Mac OS Install, or it may be named after your computer.
3	After selecting the destination, click Add/Remove.
4	Select each component that you want to add or remove.
	To further customize the installation or to remove the component, choose one of the installation or removal options from the installation mode pop-up menu.
5	Click the Start button.

Performing a clean installation

Performing a clean installation creates a new System Folder on your hard disk. The old System Folder is renamed Previous System Folder. You may want to perform a clean installation if you are having persistent problems with your computer that normal reinstallation does not solve.

IMPORTANT: Because your computer has a new System Folder, after a clean installation you must reinstall any third-party fonts, extensions, and control panels that you've added to your system or that came with programs you've installed. You may also need to reinstall any Help files that are specific to your model of computer.

To perform a clean installation:

1	Start up your computer from the Mac OS 9 software install CD.
2	Double-click the Mac OS Installer icon.
	Depending on how you received your system software, this icon may be labeled Mac OS Install, or it may be named after your computer.
3	In the Welcome dialog box, click Continue.
4	In the Select Destination dialog box, click the Options button.
5	Select the Perform Clean Installation option, then click OK.
6	Select the destination hard disk, then click the Select button.
7	Click Start to begin installation.
8	After installation is complete, reinstall any third-party fonts, extensions, control panels, and computer-specific Help files by dragging them from the appropriate locations in the previous System Folder to the same locations in the new System Folder.
	IMPORTANT: Do not move Mac OS Help or AppleScript Help from the Previous System Folder's Help folder because the newest versions are installed in the new System Folder.

Restoring your computer's original software

Some computers come with a software restore CD or a series of restore CDs which contain the Apple Software Restore application. This application lets you restore all your original software, including the system software, factory settings, and applications that came with your computer (some computers come with a separate Applications CD).

If you have a single software restore CD:
You have the option of erasing your hard disk before restoring the original software, or just restoring the original software (Restore in Place).

If you have a set of software restore CDs:
Apple Software Restore erases the contents of your hard disk and restores the original contents.

Before you begin the restore process, do the following:

•	Make a note of any preferences or settings in control panels and applications so you can easily reset them after you restore your software.
•	If you are using software that runs in the background, such as virus-protection, security, or access control software, you should turn it off before you reinstall system software. For instructions, see the documentation that came with the software.
•	If you are restoring software on a portable computer, plug it in, open the Energy Saver control panel, and set the computer so that it doesn't go to sleep. Turn off password protection in the Password Security control panel.

IMPORTANT: It is highly recommended that you back up the data on your hard disk before installing system software.

To restore your computer's original software using a single software restore CD:

1	Insert the software restore CD into your drive.
2	Restart your computer and then hold down the C key so the computer starts up from the CD.
3	Open the Software Restore application.
4	Follow the instructions that appear onscreen.

To restore your computer's original software using a set of software restore CDs:

1	Make sure you have all the Apple software restore CDs that came with your computer.
2	Insert the first software restore CD into your drive.
3	Restart your computer and then hold down the C key so the computer starts up from the CD.
4	Follow the instructions that appear onscreen.

Problems reinstalling system software

If you can't start up the computer using the software install or software restore CD:
Your computer may still be using the system software on your hard disk to start up. With the CD inserted, open the Startup Disk control panel and click the CD icon. Then restart the computer. After you install the software, reselect your hard disk as the startup disk.

If the files on your hard disk disappear when you start up from the software install or software restore CD:
Your hard disk may have been formatted with Mac OS Extended format (a new method of formatting hard disks that allows for more efficient use of hard disk storage space). The files on your hard disk will become visible again when you start up your computer using a disk with Mac OS 8.1 or later.

If the Installer cannot repair your hard disk:

•	If you see a message that your hard disk can't be fixed because a file is open, quit all programs. If file sharing is on, turn it off. Then try installing again.
•	Try using Disk First Aid or a third-party disk repair utility to repair the disk.
	If you don't have a third-party utility, or if that utility can't repair the disk either, you may need to reinitialize the hard disk.

If the Installer cannot update the hard disk driver:

•	If you don't have an Apple hard disk or if you've updated your Apple hard disk with a non-Apple disk utility, use that disk utility or the one supplied by the disk's manufacturer to update your driver. Make sure to get the latest version of the utility.
•	You may need to reinitialize your hard disk before you can update the driver.

If there's not enough memory to use the Installer:
Make sure you are starting up the computer from the software install CD.

If the System file cannot be modified:

•	You may have virus-protection software installed that guards against modification of the System file. Make sure you are starting up the computer from the software install CD. Drag any virus-protection software out of the System Folder and try installing again. You can put the virus-protection software back after installation.
•	The System and Finder files may be locked. To see if your System file or Finder file is locked, open the System Folder and select the System or Finder icon. Then, open the File menu and choose Get Info. To unlock the file, click the Locked checkbox to deselect it.

If the installation is not successful:
Make sure the Mac OS 9 software install CD is the startup disk, then try installing system software again. If the installation is still not successful, try performing a clean installation, as described above.

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