What is the difference between Product Registration and Product Activation?
Quoted from the Microsoft Windows XP Knowledge Base. There are important distinctions between activating your Windows operating system and registering it. Product activation and product registration are not the same. Activation is completely anonymous; it requires absolutely no personally identifiable information to complete. Activation is required and ensures that each Windows product is not installed on more than the limited number (usually one) of computers allowed in the software’s end user license agreement, or EULA. During activation, you can also register your copy of Windows. Registration is not required; however registering your copy ensures that you receive product support, product update information, and other benefits. The process registration takes only a few minutes to complete. Personal information (for example, “contact” information such as an email address) is required if you decide to register. You have a 30-day grace period in which to activate your Windows product i
