Can Not install macOS Sonoma
I can not install macOS Sonoma on my iMac G4
Earlier displays & monitors
If truly an iMac G4 then Mac OS X 10.5.8 would be tops you could install.
4 replies
If you have any old applications (like games) that you want to preserve (because they run on that machine and not on modern Macs), and the machine is still working, then fine. I have one of the first iMac G4s myself. It still works, it sits on display close to my Apple Silicon Mac "workhorse", and it is not going anywhere. It even has some useful features for supporting MiniDV/Digital8 camcorders (FireWire and iDVD) that are sadly missing on modern Macs.
As a platform for running modern applications and browsing modern Web sites, any iMac G4's days are over.
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Details:
Apple introduced the first PowerPC-G4-based iMacs in January 2002, and the last ones in November 2003. So we are talking about a Mac that is more than TWENTY to TWENTY-TWO years old in hardware model year terms. Even if you bought one of the last ones right when Apple discontinued it in July 2004, that would make it almost TWENTY years old!
For an iMac with a PowerPC G4 processor, the latest version of Mac OS X that you can install would be either Mac OS X 10.4.* (Tiger) or Mac OS X 10.5.* (Leopard), depending on the model. Leopard is the last version of Mac OS X that ran on PowerPC-based Macs. In the case of a G4-based iMac, I believe you would need an (iMac, 17-inch Flat Panel, 1 GHz) introduced in February 2003 (the other February 2003 iMac couldn't run Leopard); or one introduced in September or November 2003; to run Leopard.
Apple never released Tiger or Leopard in downloadable form. Just pre-installed on Macs; on optical recovery discs that came with Macs, or in retail kits containing optical discs. Those kits are LONG discontinued, although you may be able to find used ones on "marketplace" sites.
All versions of Mac OS X from 10.6.* (Snow Leopard) through 10.15.* (Catalina) are Intel-only. Big Sur (macOS 11), Monterey (macOS 12), Ventura (macOS 13), and Sonoma (macOS 14) are (Intel or Apple Silicon)-only. So Tiger is FIFTEEN major versions behind Sonoma, and Leopard is FOURTEEN major versions behind.
What is the exact year model of your iMac...?
... and what is your iMac G4 running now?
Can Not install macOS Sonoma