Problems with netgear wireless router and comcast internet

Hi,I have comcast triple-play and today I have to reset my wireless router because I forget the administrator password and the guy that setup it for me just, gone. The problem is now I can’t connected to the wireless and when I try to configure the router it ask me for IP, mask, something like “IP static resolution” i think, but also, when I connect the the cable directly to the computer it appears with limited conectivity, please help me :S I don’t know what to do.