I have a now ancient Power Mac still running 9.2. It is a brilliant work horse, but increasingly modern software, browsers, etc are not working with it. Is is possible to upgrade this to system 10 and onwards? We do have another old power mac that is running 10, but I would rather like to keep this one. It does, after all, have all of my info on it. We also have another of the latest Macs running leopard, but that has been taken over by my other half. There is not very much space left on the hard drive, so is it possible to install system io on an exterior hard drive? There is already one attached.