Further to my previous posts I had problems with upgrading from Virtual PC 2007 to the Windows 7 version of VPC. Although most of my existing VMs worked without issue one of them refused to load with a compatability error. I had problems with others not wanting to load as they were in a “saved” state that cannot be transferred to the new version. So you might want to “switch off” your VMs before bringing them over to Windows 7 VPC.
Because of the one Vm that refused to work I uninstalled the new version of VPC and went back to 2007! Everything seemed to work again without a problem.
I might try to upgrade again some time in the future.