What CPU do you have exactly?
Only CPUs that support hardware virtualisation (HV) will be able to run Windows Virtual PC.
There are 2 ways to find out whether your CPU supports HV or not:
1. View Intel's list for HV support click here to see if your CPU is supported, or
2. Run any one of these tools click here / click here.
If you have a CPU that supports HV, then this feature will need enabling in the BIOS in order for XP Mode & Windows Virtual PC to work. G