I ordered my Macbook Pro shortly before OS X 10.5 (Leopard) was released with the confidence that I’d receive a free upgrade from OS 10.4 (Tiger). While the upgrade was almost free (there was a $10 charge that probably covered manufacturing and shipping costs), it was just that. An upgrade. This didn’t bother me too much during my first round of installing Leopard as I already had a previous version of OS X installed. In fact, I never even realized that there was a difference between the upgrade and retail copies. I recently decided to format my drive and install a fresh copy of Leopard, and much to my chagrin, I discovered that Leopard wouldn’t install if it couldn’t find a previous version of OS X on the installation volume. There wasn’t even an option to verify previous ownership from an old installation disc! I thought I was going to have to do a full install of Tiger before I could install Leopard… that is, until I found the following:
Hi, I’m so annoyed regarding the broken Entourage <-> Exchange SSL root cert situation that I feel I must let others know of the following… To perform a fresh / clean installation of Mac OS X 10.5 Leopard to a totally blank/formatted hard drive using nothing but the upgrade DVD, do the following:
- Boot from the Mac OS X Leopard Upgrade DVD (hold ‘c’ while booting).
- Notice that the check for previous will fail (and "Continue" button is grayed out).
- Choose the option of restoring from a Time Machine backup and go as far as you can (note: if you do actually have a Time Machine backup, pretend that you don’t – making sure you’ve already removed any backup drives you may have plugged in).
- Now go back to (almost) the initial screen.
- Notice the "Continue" button is no longer grayed out…
- Install Leopard while drinking a beer.
Voila! Those magical steps worked and saved me the trouble of having to do a full install of Tiger before installing Leopard. Once again, I must thank the Internet for coming to my rescue!