How does MPA work?
MPA validates that the product’s Product Key, which is required as part of product installation, has not been used on more computers than the product’s end-user license agreement (EULA) allows. Generally, Windows XP can be installed on one computer, and Office XP can be installed on one computer and that computer user’s portable computer. For more information, see the EULA for your product. The Product Key information, which the Product ID contains, is sent with a “hardware hash” (a number that the computer’s hardware configuration generates) to the Microsoft activation system during activation. In Windows XP SP1, the Product Key is also sent. Activation is completed either directly by using the Internet or by making a telephone call to a customer service representative. If you install Windows XP on the same computer by using the same Product Key, the number of activations is not limited. MPA discourages piracy by limiting the number of times that a Product Key can be activated on diff
