This seems to be post SP1 in Virtual PC 2004...

New guest OSes start with the error:

"The network adaptier with address "00:00:00:00:00:00" of virtual machine <name> failed to initialize becaule the address is a null address"

Two solutions seem to be:

1. Add "<ethernet_card_address type="bytes">000*********</ethernet_card_address>
   <is_dynamic_assignment type="boolean">true</is_dynamic_assignment>" to the .vmc file, or
2. Follow suggestion at  http://blogs.msdn.com/virtual_pc_guy/archive/2005/01/17/354971.aspx, shown below.

Virtual PC SP1 Networking problems (address "00:00:00:00:00:00" failed to initialize)

There have been a number of people reporting that when they start a virtual machine - they get the following error:

The network adapter with address "00:00:00:00:00:00" of virtual machine "...." failed to initialize because the address is a null address.

To fix this problem you should use REGEDIT to:

1. Examine the key value at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002bE10318}\<nnnn>\DriverDesc to locate the desired host adapter where <nnnn> is a four digit number.
2. Look at the GUID value for the NetCfgInstanceId key value.
3. Add the DWORD key at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\VPCNetS2\Parameters\Adapters\<guid>\Flags and set the value to 0 where <guid> is the GUID found in step 2.
4. Restart the computer.

This registry value was added in Virtual PC SP1’s Virtual Machine Network Services driver. It is supposed to be setup during installation by the driver’s notify object. However, under certain circumstances the notify object of the old version is used during the installation of the new version and this registry value is never created. It is used by the driver to determine if a particular host adapter can be used in the MAC address generation algorithm. If the key is not present, we assume that the host adapter cannot be. In the case you experienced, none of your adapters appear suitable as a basis for MAC address generation and the driver returns a NULL MAC address which causes VPC to report the error.