I have a PC based on a "Intel i7 975". My OS is "Win7 Ultimate 64bit", and I have installed "Windows Virtual PC" + "XP Mode". My problem is that only ONE core is virtualized, so, can I virtualize two of my four cores? Thanks!
Do you have a win XP license? If you have one, I suggest you to use Virtual Box which can be highly customized at this point. If not, it may be possible to set the vm's process two more than one core using the task manager.