You can put 10.5 leopard on it. It won't run very fast but it works. Sent from my iPhone > On Sep 25, 2013, at 4:36 PM, bob johnson <bjohnson at nemont.net> wrote: > > I have a MAC G4 that I bought in 2001, 867mh, dual os systems, 9.1 & 10.4.11 > > I this OS as high as I can go? > > Thank You > _______________________________________________ > G4 mailing list > G4 at listserver.themacintoshguy.com > http://listserver.themacintoshguy.com/mailman/listinfo/g4