1) login to the Virtual PC; select Control Panel> System> Computer Name> Change... and enter a new name
2) restart Windows when it prompts you to reboot
3) open SQL Query Analyzer and rename the SQL Server instance
sp_dropserverGO sp_addserver , local GO
4) close virtual machine and commit changes to hard disk
5) edit the .vmc file to change the MAC address; there is one line for each network adapter,
so in a laptop I had to change two lines one for the wireless adapter and one for the wired connection
0003FFxxxxxx
6) reconfigure any applications that use the machine name or IP address