Ugh, I have a MacBook, the older one, by older I mean replaced with the new new aluminum MacBook. Well I have the installation CD for OSX 5.5, and I put it in my computer, CD loads the instructions come up, and the Install option, I click it; type in my password and it begins to restart. The CD then loads with the Leopard backround, and the language selector so I select Enhlish. I then click the arrow, and a pop-up comes up saying "Mac OSX cannot be installed in this computer." WHY?! I have the system requirements ie; Intel based, enough(more then enough) disk space, 512 of Ram? Ugh can anyone help me or am I just doing something impossible? I hope not, as a die heart Mac user I need Leopard, not Tiger. Oh yes I have Tiger (OSX 4.11) could that be why? Please help, thanks. Louis.