I can gurantee you that it won't work.... once the hardware changes then Windows won't load....
When Windows XP was on it's beta release, Microsoft was experimenting a security method for software pirecy, and that was if a user changes more then 5 hardware devices on their system then Windows Activation would get corrupted and you would need to Activate your Windows once again,,,, I'm not sure if that security setting carried on with the released version or not, but i can tell you this, if you bring your hard drive from another system then it won't work for sure
cheers
p.s: you must have lots of time in your hand
