"In an attempt to combat software piracy and thwart casual copying of its software, Microsoft is incorporating a stopgap measure that binds the ID-labeled OS to the system's hardware configuration at the time of install. Before they can launch and use XP, end-users will be required to register their copies of XP through Microsoft's website or its customer service centers."
If you add new hardware, or change something, you have to call up MS and let them know, because it's a 'different' computer. Plus, MS will potentially know your entire system config.
Among other problems.
Dk, I await your response =)