Installing Netgear wireless router?

It would seem to be a simple task ..I have installed routers in the past no problem but now I have one…I have a dell computer that runs windows xp media edition i use comcast (cable) internet connection (modem is AARis touchstone?) I am trying to install the Netgear rangemax Next wireless -N router Gigabit edition WNR854T I for some reason cannot complete the set up . is there something I am missing? I have followed the instructions to the letter with no luck…I can connect to the internet fine but have to reset my modem often times..Is there some prerequisits I have overlooked please help me cant afford to spend 150 dollars for the geek squad to come and do it for me especially when the task should be so easy to do

thanks
Cat