Windows XP must still be activated, even on replaced hardware, before it can be used without restrictions. Activation can be done either over the internet or by telephone.
Since internet activation is not available, use telephone activation as shown on the screen:
- In the Product Activation Wizard, select the correct country/region (for example, Canada in Step 1 on the screen).
- Call one of the listed Microsoft Product Activation Center phone numbers in Step 2.
- When prompted by the automated system or representative, read out the Installation ID displayed in Step 3.
- The activation system will return a Confirmation ID.
- Type the Confirmation ID into the A–G boxes in Step 4 and select Next to complete activation.
If telephone activation for this legacy product is no longer available in the region, the product cannot be activated by any other supported method and will remain in reduced functionality mode.
References: