Need help setting up a network

Hello people!I have now full control of my old (3 yr. old Vaio) laptop. I decided to set up a LAN for use with WideFS. My desktop has a A8N-SLI Deluxe motherboard with two built-in network adapters (nVidia and Marvell Yukon). One of them is connected to my DSL line. The other--to the laptop. The laptop has a wireless card, and a Gigabit network adapter (cable). The wireless card, certainly, is for the Internet, and the cable from the desktop is plugged into the Gigabit adapter in the back. Now, this is the issue--I have a home network already setup with file sharing and everything between laptop and desktop through the wireless router that I have. Now, the cable LAN, after being setup refuses to function. The little icon in the tray has an exclamation sign, and says that the connection is either not functioning or not functioning fully. I still get connectivity for WideFS through the existing network, but I lose Internet due to the fact (probably) that WideFS is taking up all of the bandwidth for communication back and forth with the desktop. What I really want to do is leave Internet connections alone, and have LAN set up via the cable connection between the Marvell adapter and laptop's Gigabit. Does anyone know how to fix this? The windows assistants failed to fix this issue, and hitting 'Repair' on the connection menu leaves the box searching for an IP address, and then popping up the error that the connection is not fully functioning.Thank you for all of your knowledgeable assistance.Cheers,