Hey there. I have a similar problem to this, and I've tried everything in this post, and nothing has worked so far.
When I tried to reset the winsock, like explained by Delphin above, it didn't work. It kinda did, but kinda not:
When I rebooted back, I tried to see if I got internet, no internet. Checked the regedit, as I'm not a fan of changing stuff in there, and I saw that only Winsock2 had gotten it re-created. There was no winsock, except my winsock.old.
So I dunno, it's still broken for me....
I've also posted a complete listing off my problem over @ Nvidia problems, due to the nature of the chipset, please check there for my complete list of my problem:
So, my Ethernet is dead.... - NVIDIA Forums
If you can help, that would be AWESOME! Thanks in advance for any pointers or tips.