Posted 31 December 2008 - 11:43 AM
FWIW: I recently encountered this when I changed a cloned C: on a different hard drive (larger) to replace a C: partition on a smaller drive.
I simply went through the activation routine for activating via the Internet.
How to activate Windows XP by using the Internet
To activate Windows XP by using an Internet connection, follow these steps:
Click Start, point to All Programs, point to Accessories, point to System Tools, and then click Activate Windows.
Or, click the Windows Activation icon in the notification area.
Click Yes, let's activate Windows over the Internet now.
Click Read the Windows Product Activation Privacy Statement, click Back, and then click Next.
Use one of the following methods:
If you want to register and activate Windows at the same time, click Yes, I want to register and activate Windows at the same time, click Read the Windows Registration Privacy Statement, click Back, click Next, type your contact information in the appropriate boxes in the registration form, and then click Next. An asterisk (*) appears next to required information.
If you only want to activate Windows, click No, I don't want to register now; let's just activate Windows, and then click Next.
The wizard establishes a connection with an activation server, and then processes the activation request.
When activation is completed and you receive the message, "You have successfully activated your copy of Windows." click OK.