ok, well check your device manager and make sure the wireless card shows up there with no exclamation points or anything.
Then, you may have to configure your wireless setup. You probably have a rounter that is configured to a specific SSID and perhaps WEP. You need to tell the card to look for these specifically. I've had trouble with the XP auto configure thing, so I always disable the XP auto configure and use the configuration program from the wireless card manufacturer.