One reason could be that your drive is simply worn down. 5 years of use, is more than i'd expect from a harddrive. Will a timeMachine backup fully succeed? Can you install onto a external firewire drive? If not, then it might be your optical drive stuck halfway... But I think the reason your machine is slow is a combination of clutter in your system and an old drive (error correction does tax the speed). Just my 2 cents. BTW if you didn't max the ram, you can't expect it to be snappy. A G4 is an ancient machine imho: come march and you should go buy a new one.