Can't Connect

This is my friends Mac and i'm a WIndows user, so i doint' know much bout them.
Lime wire syas its connected, but i notice the Networks, and it can't really connect, it isn't just LIme wire, i dowloaded another file sharing program and it had the same problems, can some one please tell me how i can connect
the comp is connected to the internet, and to a t3, she gets all websites, just can't connect. i have tried almsot everything, any suggestions are helped.
i went into system prefs, and tried to mess around HELP