Hmm .. i am not sure if it helps. But you can change the connection speed from Device Manager.
Go to Device Manager--> Network option --> right the click the option inside it. Here you have to find the option that changes link speed.
I have tried setting the speed to 1.0Gbps or having it set to Auto-Negotiate. If it is set at 1Gbps, it will not connect at all. At auto-negotiate, it only connects at 100Mbps.
Hello Andy, Try with a LAN cable to connect to another computer, if both a re 1Gbps then you don't need a cross over cable.
I tried this also. Still only got 100Mbps on the DH55HC end, while I got 1Gbps on the other PC end
Please make sure you have the latest BIOS update for the board:
Please be sure to read and follow all accompanying instructions, which can be found at this link:
If the issue persists, proceed to check your warranty options to replace the board.
I do have the latest BIOS update. I will check into getting warranty replacement.