I recently followed the tutorials for building a network using crossover cablesn and it worked like a charm the problem is that the host computer has 2 network interfaces....1 connected to the other computer and 1 connectet to a router/internet access...I can only get 1 connection to work at a time. If I pull the pci nic thats connected to the other comp then my internet connection works. if I start the comp with the card and cable in then the internet doesn't work, but it says it's connected...If anyone has any ideas?

Hi there and welcome to our forums.

It seems like you have a conflict. Probably two cards with the same IP address OR two DHCP servers disputing who is going to act (one DHCP on the router and other DHCP on Windows with Internet Sharing enabled). Make sure you followed all steps provided here:

http://www.hardwaresecrets.com/article/426

For troubleshooting, do this. Connect the two cards (situation where your LAN does not work properly) and at each computer open the system prompt (start, run, cmd) and type

ipconfig (hit enter)

Then post here the results for each computer.

Cheers,
Gabriel.