MarkCranness wrote:Just to be 100% sure (sorry), I'm suggesting:
File > Preferences > Network, and NOT
Settings > Network
Oh, I see, that is a great feature, can even add an additional interface.
To change the MAC address of the host-only adapter (NOT IP address and NOT the MAC address of your guest) you first have to determine the MAC address of the VirtualBox Host-only adapter. You can do so in the windows host by opening a command shell (start-->run-->cmd) and execute ipconfig -all.
The relevant network interface is listed as "VirtualBox Host-Only Ethernet Adapter" and will have a MAC address starting with 08-xx-xx-xx-xx-xx
Write down this MAC address.
Open your registry (start-->run-->regedit) and search for 08xxxxxxxxxx (without hyphen), whereby x stands for your specific MAC address. Somewhere in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\... you will find the MAC entry of the ethernet adapter. Change the MAC address and reboot.