Motherboard Compatibility Problem with Network Operating System

I have installed Windows Server 2003 NOS (Network Operating System) in my new computer. Everything was properly installed except for the LAN driver. I think the problem may due to NOS and Motherboard compatibility. My motherboard is Intel DH61WW LG A 11 55 Mobo. They have told me that the motherboard has a built-in LAN card; so no need for me to purchase another one. If anybody knows how to fix this problem, please let me know. I will be thankful for all the help and support coming from you.
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