This post briefly explain how Networking works and configuration options for Networking in Windows Virtual PC (WVPC). Virtual PC host application emulates Intel DEC 21140A network cards. Each VM can have up to four such emulated network cards. The ‘Create Virtual Machine wizard’ in WVPC attaches by default one or two network adapters to connect to one wired and one wireless host network adapter. Each emulated network adapter is assigned a unique MAC address in range 00-03-ff-XX-XX-XX. Last three octets are calculated using host network adapter MAC address. Each network card optionally connects to various networking options. Windows XP Mode is by default connected to Shared Networking or NAT, which’s one of four network connection options WVPC provides. Each of network adapters can be configured to connect to virtual network.
Full Article: WVPC blog