apple

A clean install is frequently applied to the Mac OS as a general (and efficient) troubleshooting technique. Non-System application programmes can also be "clean-installed".

Clean installation of the Macintosh system software / Mac OS

Until (and excluding) System 7.5

To do a clean install in system versions prior to System 7.5, proceed as follows:

  1. Locate your installation disk (Disk 1).
  2. Go to the System Folder.
  3. Drag the Finder icon into a different folder (e.g. the Extensions folder or the Preferences folder).
  4. Run the installer programme from the system installation disk.
  5. Proceed to install the system software as usual.

System 7.5

To do a clean install of the system software as of System 7.5, proceed as follows:

  1. Run the installer programme from Disk 1 or the system installation CD.
  2. At the main screen (with the Install button), press command-shift-K.
  3. Check the option "Clean Install".
  4. Install as usual.

Mac OS 9

To do a clean install of the Mac OS as of Mac OS 9, proceed as follows:

  1. Run the installer programme from Disk 1 or the system installation CD.
  2. At the main screen (with the Install button), click the Options... button.
  3. Check the option "Clean Install".
  4. Install as usual.

Mac OS X (versions 10.0.x and 10.1.x)

Versions of Mac OS X prior to Mac OS X 10.2 are notoriously clean install-unfriendly. To do a clean install of the Mac OS under these system versions, proceed as follows:

  1. Back up the entire hard drive (or portion of the hard drive with Mac OS X on it).
  2. Run the installer programme from the Mac OS X Install CD.
  3. At the main screen (with the Install button), click Options.
  4. Select all options that will wipe the destination drive clean.
  5. Install as usual.

Mac OS X (versions 10.2.x and above)

To do a clean install of the Mac OS under these system versions, proceed as follows:

  1. Run the installer programme from the Mac OS X Install CD (CD 1).
  2. At the first screen (with the Install button), click Options.
  3. Choose the Clean Install option. You may also choose to preserve all network settings.
  4. Install as usual.