To my knowledge, there is only the Microsoft site
Go to the Microsoft Help Center, type in the search bar and follow the instructions
To activate Windows online, the Windows Activation Assistant is located in the System Tools. To open a system tool, click Start, point to All Programs, Accessories, System Tools, and then click the appropriate icon, then click Activate Windows.
Follow the activation instructions that appear on the screen.
Remarks
Otherwise, you can open the Windows Activation Assistant by clicking Start, then Run and typing “oobe/msoobe /a”.
You can use your Internet connection to activate, or activate and register, your copy of Windows. Activation must be done within 30 days of installation.
If you choose not to activate Windows at the moment, reminder letters will periodically appear over the next 30 days. Once this period expires, you will be prompted to activate Windows in order to continue using it.
If you have not yet activated Windows XP, you can do so at any time by clicking the Windows Activation icon in the system tray. Once Windows XP is activated, this icon disappears from the system tray.
If you do not have an Internet connection but have a modem, click here.
If you have neither an Internet connection nor a modem, click here to find out how to contact customer service by phone.
Related topics
If online activation is not possible, to my knowledge, there will be no other option but to call
Good luck
Peterm