WiFi problems

[Pensionada]

I am using a WiFi network (router is Zyxel Prestige 2000 combined met ADSL) with a fixed antenna for my desktop and a separate USB antenna (BenQ AWL400) that I use for my own laptop or sometimes for other people's systems that need re-installation, de-virussing, etc.

This week, I have re-installed a Dell C400 Latitude laptop (Win XP Pro, McAfee 8.0, Windows Firewall); all works perfectly.
Internet connection via a fixed cable (fixed to the router) works great too, but I cannot get the wireless connection to function.

So: my own laptop works, but if I place the same antenna in the other laptop in the same physical spot, it does not: the wireless antenna is properly installed, the network is visible, the signal strength is very good, the encryption key has been correctly entered but the connection is refused with an error message saying that the connection can not be made. It seems like a software setting, but ...

Can anybody point me in the right direction, please?
Thanks
Rob

[Backdated]

Software firewall?

[Pensionada]

Software firewall?

I have tried that, doesn't make any difference.
Because I work with a lot of different systems I need to connect these different systems and I have seen the same phenomena with some desktops as well.
Typically, we are talking about clean new XP installations with either Norton, McAfee or AVG anti-virus software. Usually, the USB antenna works but sometimes without any reason that I can find it doesn't. Usually, I then unroll my 40m UTP cable and connect directly but 1) my wife hates that cable across the house and 2) this time we are talking about a laptop that has functioned with the same set-up, both with W2000 and XP.
It must be some stupid setting somewhere, but ?

[Pensionada]

Software firewall?

No, only the Windows firewall and I have tried switching it off, but that makes no difference.
Because I work with a lot of different systems I need to connect these different systems and I have seen the same phenomena with some desktops as well.
Typically, we are talking about clean new XP installations with either Norton, McAfee or AVG anti-virus software. Usually, the USB antenna works but sometimes without any reason that I can find it doesn't. Usually, I then unroll my 40m UTP cable and connect directly but 1) my wife hates that cable across the house and 2) this time we are talking about a laptop that has functioned with the same set-up, both with W2000 and XP.
It must be some stupid setting somewhere, but ?

[Backdated]

What actually happens?
Is there no signal, no IP etc or is it that the dongle isn't recognised?
Are the relevant chipset drivers for each machine installed?
Does Event Viewer give any clues?

[Pensionada]

I found the problem.
The installation disc (BenQ) for the USB antenna contains 5 drivers for the same device (heaven knows why; it is not explained anywhere); if you select the 1st one, as will happen if you are not fast enough, the driver will load OK, but not allow connection. All of the others seem to function correctly.
This is about the most stupid thing that I have ever seen .... on the BenQ support site I did not find anything.

Thank you all for your advices and sorry to have bothered you with something this trivial.
Have a great weekend
Rob

[Backdated]

It's not trivial if it doesn't work!
As for the weekend, thanks.... I intend to!