I had difficulty finding this product myself, but found it at the Micro Center under "WF-2103 150Mbps Wireless N USB Adapter" at http://www.microcenter.com/single_product_results.phtml?product_id=0376775
No driver download available and I can't even find the manufacturer to check their web site. So unless anyone else here can find it for you, it seems your only option is to go back to where you brought it and ask them for another CD.
Any chance that Windows XP will recognise this anyway and find the drivers itself? I doubt it but it is worth a try.