Can someone tell me where to download Norton Internet Security 2010 for my netbooks?

Sometime back I posted this same question, and it was answered perfectly, but I have encountered a problem trying to use the download that in the past worked great. When I try to download now, it asks for a credit card number. It never did that before, so I don't know what to do, as I already have a brand new key to use, I just need the download, as obviously my netbook has no cd drive, any help would be most appreciated, thank you, signed frustrated in Arizona.