I know XP is out of support, but for the few that are in our environment I'm having trouble authenticating over 802.1x. The wireless card kicks back "windows was unable to find a certificate to log you on to the network". Even after making some changes to the properties (Dell Wireless 1397 WLAN Mini-Card) with the 802.1x option selected and trying both options of Smart Card or other certificate or PEAP, it still doesn't connect.