When I ran up my Windows 8 box, it was connected to an enterprise LAN, and everything was tracking along just fine. When I brought the box home and connected it to my Netgear DGN2000 home router via Ethernet, I started experiencing disconnection every couple of minutes or so, with ‘network cable unplugged’ as my network status. The network connection would drop and reconnect automatically, returning after a short outage on its own. Very strange.
None of my existing computers had any problems connecting through this network and I initially misdiagnosed this as a problem with my Hyper-V virtual switch settings, thinking perhaps the servers sharing the same network connection was causing the problem.
Well. As I will often do, it turned out I was massively over thinking the problem. When Windows 8 started using the Ethernet adapter Intel(R) 82579V Gigabit Network Connection, it set itself to “Auto Negotiate” on the adapter’s network speed settings and the Netgear router didn’t take kindly to this, disconnecting the machine every few seconds. It would seem my router has developed a fault with the Ethernet ports, possibly related to overheating (I have always had the device propped up on two cassette tapes to aid airflow, however it still runs pretty hot). It doesn’t mind the PC connecting at 100mbps full duplex however, so I’ve resorted to that for the time being.
To get to the below options, access Device Manager > Network Adapters > Ethernet adapter properties > Advanced Tab. Setting it back to 100 Mpbs full-duplex fixed the issue.