I have the same MoBo with two Ethernet ports. I have just installed Win7 Pro 64 O/S. Original disk that came with the MoBo does not allow Ethernet drivers to be installed (option is disabled), though ethernet ports are enabled in BIOS. I've downloaded & installed latest drivers from nVidia site and still network ports are not functional. I hate to add a NIC card when MoBo has 2 built-in ports. I have read on another forum that older drivers for Vista 64 bit may fix this issue. Does anyone have similar problem? If so, have you disabled nVidia driver updates?