WRT54G, unable to install router

Question

I've used this router for one year, and up until this week when I room mate was unable to log on to the wireless.
I uninstalled the Linksys software and use the CD I got with the router. The system was unable to detect the ethern net cable and as a result unable to connect to router.

I have access to internet via my cable.

Would like some assistance in getting the software need to conncet the router to my lap top and then my roommates wireless PC