Currently Being ModeratedOct 6, 2012 8:39 AM (in response to MarthaT)
It's because the 10.6 your attempting to use is machine specific with hardware drivers for that model of Mac only.
You will need the 10.6.3 white retail disks, call Apple via phone to order.
BTW, a 10.5 era machine may not run 10.7 or 10.8, or may only run 10.7, or if it does run either may do so slowely and wont' run your older PPC based software and hardware drivers.
You might even have to upgrade RAM, so be sure of your hardware requirements and expect to replace some software with new copies.
IMO it's best to stick with 10.6.8 on most pre 2010 issue Macs.
Currently Being ModeratedOct 6, 2012 10:52 AM (in response to MarthaT)
Thanks for the prompt reply. I called 1-800-mymac and ordered a disk for 19.99. The guy checked out my system to make sure it would be compatible. Love those Mac people!