Sounds exactly like the same problem I had. I tried everything, different settings, router, cables...etc. I don't recall if downloading the latest NIC exe installer, or using the utility ( at http://www.intel.com/p/en_US/support/detect/?iid=dc_spotlight_dctop10 ), or the Device Manager, NIC, Properties, driver update finally worked for me.
It was definitely a bug, it was driver related, and I saw the driver update wasn't working porperly. What I found finally fixed this was install the NIC drivers... but the trick was the right ones. For some reason Windows was always installing old drivers files even when I was using the latest driver version installers. Maybe the install bug that wasn't fixing a driver bug was resolved in the lastest driver update.
If you haven't already, make sure you have the latest BIOS firmware in, chipset drivers in, then the NIC.
The thing to watch is the driver version numbers to see if they have been updated after upgrading the NIC driver files.
Hope this helps!