Imran,
to CF
First problem - the modem only supports ONE connection. In this case it should be the ethernet cable from modem to the router - you USB cable should not be connected now. You also need to power off the modem for 30 secs each time you change cables.
Does your laptop have an ethernet connection? You will need an ethernet link between one of the computers and the router in order to setup the wireless link. If the laptop doesn't have ethernet either, you will prob need to get a £5 ethernet card from PCWorld.
Once you have a working ethernet connection from a PC to the router you should be able to follow the Netgear setup instructions.
HTH