Rather annoyingly Virtual PC 2004 & 2007 set the default folder location for Virtual Machine Configuration (.vmc) and Virtual Hard Disk (.vhd) files to a folder called My Virtual Machines in your My Documents.
This means users could inadvertently end up saving huge VPC disk images to their My Documents folder, not good if you use profile roaming

Luckily we can add a new environment variable called MYVIRTUALMACHINES with our preferred default location.



The next time Virtual PC is loaded it will pick up the environment variable as the new default.