Slow network file transfer (under 20KB/s) on newly built x64 Win7

I'm not sure if you're still having this problem but I found this post after having the exact same issue.

I have the same motherboard as you and I'm using a 64-bit installation of Windows 7 connected to my home network using gigabit Ethernet.

I managed to find a solution after reading another super user question and some experimentation:

I went to the configuration screen of my network adapter and changed the following configuration settings:

• Large Send Offload V2 (IPv4) = Disabled (was Enabled)
• Large Send Offload V2 (IPv6) = Disabled (was Enabled)

I guess this is a driver issue. I haven't scouted out for an updated driver so I'm not sure if there is a newer version (and whether this issue is fixed).

This has solved this frustrating problem for me. I hope it helps you.

Check link speed and duplex under the network adapter settings. Change to auto negotiation if anything else is selected. This took me 6+ hours of troubleshooting. This site finally had me looking in the right place.