Windows XP Home version with bootcamp

One thing you could do is use VMWare Converter or Parallels Transporter to turn your old running PC to a Virtual Machine (VM) on Fusion/Parallels Desktop. This is a so-called Physical to Virtual (P2V) migration. It may still require you to reactivate the OS, and retire the old PC, but it generally does work.

"P2P" (Physical to Physical) migrations are generally not supported or recommended. Not just from the licensing point of view, but Windows usually doesn't take well to massive hardware changes. You generally need to reinstall.

On the licensing front Microsoft's licensing model is pretty simple. If you want to be able to move a license from one machine to another, you need a full retail copy. They come with transfer rights. OEM licenses, like the ones you get pre-installed on machines do not generally come with transfer rights.

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