I've recently had an issue with my main desktop machine losing network connectivity overnight. No other machines are affected, only my desktop one. The problem computer is connected via wired ethernet to a Netgear GS105 Gigabit switch. The lights on the switch stay on, so there appears to be nothing wrong with the physical connection but the system still can contact nothing on the network.
What has worked as a fix, was to go into the network connections, disable and then enable the LAN connection. The computer will then work fine for another 24 hours.
After some searching, I read this:
http://forums.techarena.in/vista-help/791873.htm
Which then led to this:
http://support.microsoft.com/kb/927168
Now, each time the connection has stopped working, I have had my Windows Mobile 6.0 phone plugged in, synchronising and charging. I wondered if this was the same as Internet Connection Sharing as the phone is given an IP and can access the network via my desktop computer. When I had
network problems with my network camera, I do remember switching on RSS (receive side scaling) as part of the changes made to the IP stack.
I've disabled RSS for now using the command:
netsh interface tcp set global rss=disabled
I'll followup with any further lockups or not!