can't load internet radio

I have two new Dell computers which have wire connection to a switch then to a router for the internet connection.  I am able to surf the net without any problem.  However, when I tried to load the internet radio, e.g. XM radio (when it shows "connecting to media..."), then my computer not only lost the internet connection, it also shuts down the router.  I have to reset the router in order to have internet connection.  This problem only occurs with two Dell computers.  I have two other computers which have wireless connection to the router.  Those two non-Dell computers have no problem accessing and loading the internet radio stations.  I have hired two IT persons, but none of them know what is going on.  I suspect there is some types of software conflict inside of two Dell computers.  Can some one help me out?  I have already spent too much money hiring people who can't figure it out.  And when I call Dell tech support, they sort of blew me off.