well I know that if my computer phyically supports it I can install it, what I'm wondering is, will the upgrade install option be highlightable? Or will it be there and I can't select it?
if you're asking whether you can upgrade from OSX10.1 to OSX10.3, yes you can, but you'd need to buy a copy of OSX10.3 to do it. The combo updater alone won't do it.