I am operating my macbook pro with OSX 10.5.8. I need to upgrade to Snow Leopard 10.6.3 for a new application. Can I load it on a external drive ?

  • Asked about:  Mac OS X 10.6 Snow Leopard

1 Answer from the Community

  • Yes, you can. (If you have an intel-based Mac with at least 1GB of memory.)

    If you have purchased a retail version of Snow Leopard, do an "erase and install" on your external drive (this will reformat the external drive to make it suitable for Snow Leopard).

    If the Snow Leopard DVD does not give the option to automatically do a clean install (erase and install), then follow these steps:

    1) In order to do a clean install with the $29 DVD, you will have two options when you start up from the DVD... "Utilities" or "Continue". Select "Utilities" and when the Mac restarts, select "Disk Utilities" from the "Utilities" menu. Do a format of your external drive and then QUIT "Disk Utilities".

    2) Now Snow Leopard will begin installing. During the install, it will search your Mac for all other partitions with an older OS and then ask you if you want to import your OS Settings, Applications and Files from one of those other partitions. Do this for a very smooth upgrade transition to the new OS. (If you decide to not import, then you will end up with a clean install of Snow Leopard instead.)

    3) Restart and hold the Option key to be able to select the external drive as your start up disk. After restarting with the newly installed Snow Leopard, go to the Apple Menu and do Software Updates to bring your system up to OS 10.6.8.

    4) Whenever you want to switch between operating systems, press Option as you startup or restart your Mac and select the drive partition with the other operating system. Or, go to System Preferences and select Start Up Disk.