NetStumbler doesn't work on Vista. You're secure enough with a LiveBox, it won't allow anything to connect without you pressing the association button on the side and comes with WEP enabled by default (not secure itself, but in combo with the first measure it's good enough).
You can do what NetStumbler does from Vista if you'd like to try it;
Open a command prompt as administrator
netsh (press return)
wlan show networks mode=bssid (press return)