Had a similiar issue after installing Vista SP2....
Had ZA Free on Vista 64 with SP1 running fine using a linksys USB wireless adapter.
Seemingly after updating to Vista 64 SP2, the wireless adapter would not "enable" correectly. Wired LAN worked fine.
Saw a thread out there about possible ZA conflict with Vista's WLAN function.
Had to Uninstall ZA completely...Rebooted and Poof.... Wireless was up and running like a champ.
As a test I downloaded my ZA Free again from the CNET site...previous download was from Sept 9, 2009 (or so).
Re-installed ZA Free from today's download...
Wireless is still up and running fine !!