



A dialog sheet appears and presents you with several installation choices. If you prefer not to custom install Leopard, simply install the software using the default installation method. To do a custom install of Leopard, click the Options button that appears when choosing an installation destination. Below describes what each type of installation provides.
Upgrade to Mac OS X, Install Mac OS X
When booted from the install disc, the installer will present one of the above choices to you, depending on which volume you've selected for installation. If a previous version of Mac OS X is on the selected volume, "Upgrade to Mac OS X" appears. If no version of Mac OS X is installed on the volume, 'Install Mac OS X' appears.
-About Upgrade to Mac OS X
Upgrading to Mac OS X (default installation method) is the least intrusive way to install Leopard. Most of your existing settings and applications are left untouched during the upgrade. You won't have to configure a lot of settings afterwards.
If you're having issues with your currently-installed version of Mac OS X, using the upgrade method may not resolve those issues. Instead, you might benefit more from doing an Archive and Install installation described below.
-About Install Mac OS X
Install Mac OS X appears when the installer finds a destination that does not already have Mac OS X installed. If parts of Mac OS X are missing, this option may appear instead of 'Upgrade to Mac OS X.' If the selected volume can't be upgraded or software can't be installed on it as is, this choice will be dimmed.
Archive and Install
This type of installation moves existing System files to a folder name 'Previous System,' then installs a new copy of Mac OS X.
This option leaves non-Apple-installed (third-party) items intact, though they may be moved, depending on their location. Usually it's best to reinstall third-party software after an Archive and Install installation to ensure they work correctly.
The Preserve Users and Network Settings option (selected by default) imports existing user accounts, their Home folders, and your network settings into the new system after installation. If you deselect this, you should have a current back up your important data, network settings, and user Home folders available. The Mac OS X Setup Assistant will not appear after this kind of installation.
Erase and Install
This option, also known as a 'fresh install,' completely erases the destination volume, then installs a new copy of Leopard. This is the fastest way to install Leopard, but it may take some time to set up your computer after installation. You will have to configure all of your computer settings, install your third-party and iLife applications, and restore your personal files from the backup you made.
Personally, being that Leopard is a totally new operating system, I'm going to use this install method. It's like starting on a new computer again, and should eliminate any current issues I have with Tiger.



