Buffalo doesn't offer XP x64 drivers for their 802.11n (draft) cards. This driver is a mix between the original Broadcam chipset driver and the Linksys WMP300N driver with edited inf file. Windows will detect the WMP300N, but the card works. Since this driver is my own creation, use it at own risk! May work for other cards based on the Broadcom chipset, if Windows ident them as DEV_4329&SUBSYS_03531154.