-- Ben Armstrong, Virtualization Program Manager
Talking about core virtualization at Microsoft (Hyper-V, Virtual PC and Virtual Server).
A regular question I hear is "How can I stop Virtual PC from storing all of my virtual machines in the 'My Virtual Machines' folder in 'My Documents'?". The answer is simple - but obscure. To change this you need to create a system environment variable called 'MYVIRTUALMACHINES' with a value of the path that you want Virtual PC to use for the default location for storing virtual machines.
Cheers,Ben