To activate Windows by phone
The Windows Product Activation Wizard is located in System Tools. To open a system tools item, click Start, point to All Programs, point to Accessories, point to System Tools, and then click the appropriate icon., then click Activate Windows.
Follow the activation instructions that appear on your screen.
Alternatively, you can open the Windows Product Activation wizard by clicking Start, then Run, and type in "oobe/msoobe /a".
If you do not have a modem or an Internet connection, you can activate your copy of Windows by calling a Microsoft customer service representative. Activating Windows is fast and does not require your name or other personal information.
If you have not yet activated Windows XP, you can initiate activation at any time by clicking the Windows Activation icon in the system tray. Once you have activated Windows XP, this icon disappears from the system tray.If you choose not to activate now, reminders will appear periodically during the next 30 days. After that time has expired, you will be required to activate in order to continue to use Windows.