Right now I am connected to a wireless network with a linksys wireless usb card. I have an onboard network card and I am trying to connect with my Xbox through gamespy to play Halo online. On the website it says i can hook up the Xbox to one network card and hook up the internet normally on the other. The question I then have is how I do I get the computer to recognize both the internet connection and the connection to the Xbox. I can enable both of the devices but the wired one that is connected to the Xbox says that a network cable is disconnected and it doesnt recognize the Xbox. Ultimalty what I am asking is how do I get both my lan cards working at the same time?

Well this doesn't quite answer your questions, but you do have a router right? A wirerouter and access point? If you do, I have a similar set up, I use Xboxconnect, and have xbox connected directly to the router and pc connected to router (via cable or wireless). You have to open up a few ports on a linksys, and you run the xboxconnect program on pc, and the program can detect it on your "network". It can detect the xbox searching for lan games, and the xbox actually does support routers pretty well even for lan stuff which I have been suprised by. Only problem is lag on halo online, half the time its un playable, but alot of the time, it can be very good. I dont know what the set up you are trying to do would work for gamespy, i got gamespy to work with that set up as well, but not as much lag in xboxconnect. Try them as well.

To get xbconnect, go to xbconnect.com heres a pic of how to set up the network http://www.xbchelp.com/network/