This policy setting allows the Network Access Protection (NAP) client to support the Windows XP version of the 802.1x Enforcement ...

This policy setting allows the Network Access Protection (NAP) client to support the Windows XP version of the 802.1x Enforcement Client component.

If you enable this policy setting, NAP allows the Windows XP version of the 802.1x Wireless Enforcement Client to participate. 

If you disable or do not configure this policy setting, the Windows XP version of the 802.1x Wireless Enforcement Client cannot participate in NAP.