Is there a way to use a Linksys WRT54GC strictly as a switch for two wired computers?

Im trying to get two computers to communicate with a Linksys router that a friend of mine loaned me. Im using wired connections. I dont have highspeed internet to hook to the router. I just want to use it as a plain switch. Are there settings that can be used to do this? It does NOT work as a switch straight out of the box. Linksys says it WONT work unless I have a highspeed connection first. Does anyone know how to fool it into thinking it has a highspeed connection via settings? I dont really need to hear other options, just how to do this if there is a way. Thanks in advance.