I cant find a fix please help

[heavy2healthy]

I search all over the net and no fix. I have a late 2009 macbook, I installed winxp sp2. So far so good and then I try to set up wireless. It keeps telling it cant find the certificate for dlink its a n router but every thing in the house runs on g on it. The macbook wants to use N is that the problem? I keep correcting the settings once I hit ok. It seems to go right back to wep ( I use wpa) and looking for a smart card. I then download bootcamp 3.1 and its still the same. hard wired the internet rocks but I need wifi. Is it because its looking for N ? Is there away to have the card use G?