Only wireless B (11 Mbps) and WPA encryption is not supported in Windows.
Link is broken. Drivers can be obtained from proxim with free registration from this address: http://support.proxim.com/cgi-bin/proxim.cfg/php/enduser/std_adp.php?p_faqid=1082
Only useful today in Linux, where the latest driver supports WPA encryption. The wireless B speed of 11 Mbps is still faster than most internet connections and is thus not a problem.