Why does a "Thank You" message appear when connecting to the Windows Update Web page?

The complete version of the message is as below:

Msg:
Thank you for your interest in Windows Update. Windows Update is the online extension of Windows that helps you get the most out of your computer.....
To use the site of the latest version of Windows Update, operating systems such as Microsoft Windows 98, Windows 98 Second Edition, Windows Millennium Edition, Windows 2000 (except Windows 2000 Datacenter Server), Windows XP and Windows Server 2003 family should be running.

The message appears when the following conditions are met.

a. Firewall function for the Internet connection is enabled
b. Norton Internet Security 2002 is installed and is currently running

For more information, please refer to the following solution in Microsoft's technical support website:
Article ID: 817144
Title: "Thank you for your interest in Windows Update" message when you connect to the Windows Update Web site.
Last reviewed: 7th May 2003