Microsoft Product Activation is a DRM technology used by Microsoft Corporation in several of its computer software programs, most notably its Windows operating system and its Office productivity suite.
The procedure enforces compliance with the program's end-user license agreement by transmitting information about both the product key used to install the program and the user's computer hardware to Microsoft, inhibiting or completely preventing the use of the program until the validity of its license is confirmed.
Immediate activation is not required following installation, but the program must be activated within a specific period of time in order to continue to function properly.
Throughout this grace period, the user will be periodically reminded to activate the program, with warnings becoming more frequent over time.
Activation by telephone requires that a user and a Microsoft agent verbally exchange activation information.
The procedure has been met with significant criticism by many consumers, technical analysts and computer experts, who argue that it is poorly designed, highly inconvenient and ultimately does nothing to prevent software piracy.
When installing a retail copy of Windows or Office, the user is asked to input a unique product key supplied on a certificate of authenticity included with the program, which is later verified during activation.
In this case, the copy of Windows installed does not use the product key listed on the certificate of authenticity, but rather a master product key issued to OEMs called a System Locked Pre-installation (SLP) key.
When activation takes place, the program saves a record of the verification data in the user's computer.If the system is booted up with significant hardware changes, the application will likely require reactivation to prevent the same copy of the program being installed on two different systems.