Network issues

[Nitristion]

I currently have two networks setup in my house. One is a wireless network, that is protected by a WEP key, and the other is a purely cable based network. The wireless network is supposed to be totally seperate from the cable network, and as such I have 2 routers and 2 internet lines. The wireless is a fairly cheap one, and the cable is my fast download/gaming line, reserved for just my PC and a server I've setup.

My PC has a wireless card, for those "just incase" scenarios, and I recently found that I could connect my wireless laptop through my PC and use the faster internet line, as long as my PC was conencted to both networks.

Is there any way to stop this connection? I have stuff I'd like to keep seperate and safe on the cable network (personal files, etc) and I know its fairly easy to hack into a WEP secure wireless network.

My PC is not set to share its internet access, so its not that. Any ideas?

 

[Nitristion]

Are the 2 networks on 2 different subnets?? ie, wired is 192.168.0.0/24 and the wireless is 192.168.1.0/24? I assume that they are.
The only way that the PC would (should) be routing from one network to another would be if there was something in the routing tables causing this.

Can you post a "route print" from the PC with the 2 NICs?
If there is any public IP address in there, then feel free to anonymise that part.

Each network has its own router, and totally different internet line. provided by two different ISPs. But if what you say is true - I'm not an expert on networking - how would I produce a route print?

What OS is on the main PC?
If Vista, try disabling the ICS service itself.
I dont have an XP machine to hand, but I think the ICS service goes hand in hand with the windows firewall service. If you dont use the firewall then that should be no problem so disable the service.

Another consideration would be the default gateways on each card when they are both enabled. Multiple gateways will mean the wired connection's gateway will invariably take priority.

This still doesnt explain why the the PC is effectively acting as an AP
Without manually bridging the two connections or using ICS, I really cant see how this could be happening.

The PC is running XP, so is my laptop, and the other laptops that connect to the wireless network also run XP.

Windows firewall is off, I've got Zone Alarms on all machines.

ICS? Where would I find & configure this?

Also, I have not accidentally bridged the network connections, that was the first thing I checked

 

[Nitristion]

My PC is not set to share its internet access, so its not that. Any ideas?

Just go into the adapter properties and unset the option to allow other users to share the internet connection. Or right click + disable the wifi adapter.