Power Mac - how do I enable WLAN card - what is it?

Hello, I have an older G4 power PC and I just got a netgear USB wireless receiver. It works intermittently and sometimes it says "enable WLAN card" when I have no connection. I don't know what the WLAN card is, if I have one, or how to enable it.
I just know that the netgear card has worked intermittently. I try to mess with settings and sometimes that works. I try to keep those settings but either they automatically change (even though I lock the settings) or something is wrong. I mess around with settings and sometimes it works again, other times not.
thanks,
M
Oh mac osx 10.4