I got HP DC7800 USDT running Windows 7 32-bit. Installed.. Mikrotik RouterOS 5.20 in Virtualbox. I managed to add Apple USB Ethernet Adapter as 2nd ethernet. 1st ethernet is a built-in NIC.
How do I configure mikrotik?
please use newer RouterOS like v6.15 and follow this wiki article how to configure the router:
http://wiki.mikrotik.com/wiki/Manual:Initial_Configuration