I have lap top W / internet & home phone--need to hook up netgear router to netgear modem for WiFi---netgear instructions do'nt work because I do'nt have a second device & Comcast wo'nt connect them ???
You need to be more specific as to what models equipment you have are and what exactly you're trying to do here.
All you should have to do to get them connected is unplug any ethernet cords going to your modem and power cycle it. Once it loads back up plug an ethernet cord from the modem into your router and go from there. You should be able to finish any setup with your laptop from that point.
Some routers will come with a pre-generated password that is usually located on a label somewhere on the router. You can always plug another ethernet cord from the router into your laptop and set the wireless up that way if you aren't able to get on the wifi network.
FWIW, they are looking for makes and model numbers, not serial numbers.