Microsoft uses product keys for Windows XP Professional to ensure that individuals use the software in a manner consistent with the license agreement. Individuals may encounter difficulties when trying to use the same product key to install Windows XP Professional on two or more computers.
Microsoft maintains an activation system for Windows XP to encourage users to comply with the license requirements. Using the product key and information derived from a computer's specific hardware components, Microsoft generates a unique number referred to as an installation ID. This information is ultimately used to register one product key to one specific computer.
IT professionals may work with two types of product keys, generic and machine-specific. Generic keys are useful for initial stages of setting up Windows on numerous computers. Machine-specific keys are used in later steps of computer deployments and uniquely represent legitimate software licenses.