Can I only allow 1 active NIC at one time?

Does anyone know of a software app, configuration or GPO that can only allow
one active network interface card at one time?

We need to stop people from having a Lan connection and a Wireless
connection at the same time. The reason is that our McAfee firewall doesn’t
implement rules at the interface level. Therefore if we have an internal Lan
connection and a wireless connection by accident to someone else’s network
the firewall thinks that it is internal and allows Incoming traffic. I can’t
rely on just the telling the users to not turn on their wireless when they
are connected to the internal Lan.

We are using Win XP on a corp network with Win2000 AD.

I am looking for any Windows config, bios setting or 3rd party apps that cab
only allow one active NIC then this network bridging issue goes away and the
firewall will work properly again.

I do have a script that does disable wireless but I cannot find a proper
trigger point to run it. Sometimes our users boot up their laptop then plug
into the internal Lan so running this script in a login script won’t work
that well. Does anyone know if there is a way to run this script anytime the
Lan connection is plugged in?

Any help would be greatly appreciated.