Ask Max: Upgrade OS on a used Mac
I am considering buying a pre-owned (used) iMac which will have an older version of OS X (like 10.2 maybe).I currently also have a Mac mmini running OS X 10.4.8. Can the install disc for my Mac mini be used to upgrade the OS on the older Mac?
There are several complications with installing newer system restore disks on older equipment. The first complication comes from the difference between the PowerPC and Intel versions of OS X 10.4. If your Mac mini has an Intel processor, then the version of OS X you have will not run on the older PowerPC iMac. Even if your Mac mini has a PowerPC processor, those grey discs that came with the Mac mini will not install on any other type of Mac. Apple tries to prevent you from using those discs because it is technically stealing an OS sale from them. If both computers are PowerPC-based Macs, you could use a program like Carbon Copy Cloner to clone your 10.4.8 system onto the iMac. That would give the iMac OS 10.4.8, but it would also include all your data from the Mac mini. Mostly, it is best to upgrade the operating system from retail discs. The good news is that this year 10.5 will be released, and then you can buy a copy of that upgrade for your systems.
We also sell install discs of varying versions separately from our used Macs, so if you're looking for a particular version, we may be able to help you there. We don't include OS CD's with our used Macs because many of them don't come with when we acquire them, and often customers aren't in need of the discs anyway, so we make them available separately for those who do.