I need Help with Comcast Modem?

It isn't a modem to begin with. It's a router and it connects to your modem. It will cost you dearly if comcast has to set it up for you. It won't cost anything if you slip the disk in and set it up yourself. Lastly, you need to find out why your wireless doesn't work before you throw money at it to fix a problem. A new router is most likely not the answer.