There is a few new options in the NETSH command in Windows Vista that may help you diagnose problems with wireless network connections.
Type netsh wlan show network mode=ssid
To display infos about each visible SSID
Type netsh wlan show network mode=bssid
To display infos about each visible SSID, antennas, signal strength, radio type and channel.
More infos : technet2.microsoft.com
