I am helping a friend upgrade a three year old iMac from 10.4 (tiger) to 10.6 (snow leopard), she has purchased all the software 10.4, 10.5, and 10.6 upgrade. For some reason she never moved to 10.5 even though she had the DVD. In addition I wanted to have a "clean install". The first thing I did was make a backup of all of her files. Then I booted 10.4 from DVD and used disk utility to erase the hard disk. Next I booted 10.6 from DVD and selected English as the language, then I get the following error: "Mac OS X can't be installed on this computer. It requires a previous installation of 10.5." Do we really have to go from 10.4 to 10.5 to 10.6? What a pain in the butt!!! Any ideas on how to skip 10.5? I already erased the hard disk. Here is a link that recommends a clean install: http://www.cultofmac.com/how-to-upgrade-to-snow-leopard-the-right-way/15141 Thanks for the help.