Snow Leopard: What you should know about… Installation
The Snow Leopard Installer has been revised over previous versions, and no longer has separate “Upgrade” and “Archive & Install” options. You can still choose to perform a clean install, by invoking Disk Utility when booting from the DVD.
The clever parts of Archive & Install have been rolled into the Upgrade logic, and so what Snow Leopard does when you install it is a combination of the two. Known-to-be-incompatible extensions will be automatically disabled as part of the installation.
If you’re upgrading from Leopard and don’t need to perform a clean install, you should run the installer straight from Finder in Leopard. Unlike previous versions, Snow Leopard’s installer doesn’t simply reboot if you run it under the previous OS.
Also, if your installation is interrupted for some reason part-way through, Installer should pick up where it left off if you boot from the DVD. I haven’t tested this, though.
If you choose to Customise your installation, various printer drivers, Rosetta, and the QuickTime 7 Player are all optional installs. The Installer is quite smart about upgrades, and will install the QuickTime 7 Player if it detects a QuickTime Pro registration key on your current installation (you don’t need a key to install it, but it won’t be automatically installed otherwise).
If you need to install additional printer drivers after the initial installation and don’t have your DVD handy, you can grab them from Apple’s support website.
If you use ODBC, you may also want the ODBC Administrator for Snow Leopard, which is no longer included in the default install.
If you don’t install Rosetta and attempt to run a PowerPC application, Finder will prompt you to install it (rather than displaying a generic error about not being able to launch the application). At this time, Rosetta isn’t available as a download from Apple’s support site.
