The phone activation system was, at one time, extensively utilized for product activation, including that of Windows and Office, enabling fully offline operations. Once users input a specific key, the product generates a corresponding Installation ID. Users can then obtain an Activation ID by entering this ID over the phone, thereby completing the activation process. As of December 3, 2025, Microsoft has ceased providing the Windows phone activation service. Consequently, users are now required to access a designated website for online activation. To address offline activation requirements, Microsoft has offered alternative solutions; however, the process has become more intricate.
