Odd -
This error is usually caused by a failure to connect properly to the server - it's a 'Connection Aborted' error, and usually implies that there is a firewall problem, or a simple bad internet connection (I get it fairly frequently, as I use a 3G connection).
I suggest opening an Elevated Command Prompt window, and running the following command
NETSH WINSOCK RESET
- wait for it to complete, and reboot on request.