I have a windows server 2003 R2 instance running in a hyper-v instance on windows 8. I have setup an internal switch that uses internet connection sharing to get out to the internet. It works fine except for when I try to do windows update on the server 2003 instance it disconnects my remote desktop session to the windows 8 hyper-v host. When I reconnect it says windows update failed. I know that sounds crazy but I have tested it over and over again. If I change the instance to use my external switch (I have an external switch defined on another network adapter) windows update works fine.