Now mark me confused. I did a clean install to the root of my HD. Still no render node or render node installer visible. Tried the 5.1 render node updater again, just in case. It ran! It even claimed to be installing files somewhere --- where, it wouldn't say. I still have no idea how to install the render node on a networked machine, or how to start it on a networked machine (as the Carrara manual indicates). All I know is how to network render, once the nodes are up and running. Not a big help at the moment.