Originally posted by: NWRMidnight
get rid of the default gateway on the 2nd nic. I had 2 nics in my machine, one for internet, connected to my cable modem, the other for my home network with my kids machines. I had the 1st nic setup to automatic get IP and such from the cable modem. The 2nd was set at 10.0.0.1 subnet 255.255.255.0 and NO default gateway. The reason I had no default gateway is because this network has no access to the net, so it is not needed.
What is causing your problem is you have a default gateway of 192.168.0.1 and when you have both nics enabled it is trying to find the internet thru that gateway, which is not available. If you leave it blank, it will not attemp to access the net thru the gateway on the xbox lan and it will work as you want.
Another option is you can buy a router and connect both pc and xbox so you can access the net with your xbox to play online with friends. I finally went this route so my kids machines have access to the net without having to start up internet shareing so I can update them, I just block the internet at the router so they can't get online without me being around, not that they need to since they are quite young still. 😀
Daniel