Hardware Assisted Virtualization
I started downloading XP Mode and Virtual PC before noticing their tool for determining if a computer is able to run them. When I did run this tool, it said that my computer doesn't have hardware-assisted virtualization and couldn't run Virtual PC.
This leaves two questions...first, what hardware is required to run Virtual PC? Second, will XP Mode work without Virtual PC? Seem odd that they used these features to promote the sale of the Pro version of W7, yet said nothing about hardware requirements until now.