Cannot connect to the internet. I purchased a new HP laptop yesterday and I cannot get it to

Question

I purchased a new HP laptop yesterday and I cannot get it to connect to the internet. I have Comcast High Speed Internet and when I try to set it up, it asks me for a user name and password supplied by Comcast. I have no idea what it is talking about and my other computer didn't have the kind of hook up problems. Both the new and old computers are running Windows Vista.

Thanks,

David