installing a netgear router

i bought and followed instructions for installing a netgear wireless g router.  i hooked up my broadband modem to the router, but then i get a popup stating i'm in conflict with another network ip address and so i can't make a connection to the internet.  i don't have another network installed, so i'm wondering what i need to do to get around this.  there's no information in troubleshooting for this in netgear manual.  any thoughts?