I have a Windows 2012 server running VB 4.3.12 with a Windows 7 guest. When I reboot the server (Host) the NIC will not reconnect unless we login locally and disable/enable the NIC at which point it goes back to normal. Prior to that is just says limited or unidentified network. I have been able to reboot the server and have it work by disabling the "VirtualBox Bridged Networking Adapter" prior to restarting. Though it then has to be enabled to start the guest after the reboot. I have not seen this issue on other servers with the same OS so I do not think that is the issue. The host NIC is up to date as is the host OS with drivers and updates. The NIC is an "HP Ethernet 1 Gb 2-port 330i Adapter".
Thanks for any assistance.