This is common practice from Microsoft. From Windows XP EULA: Use of Previous Version Of Software. In lieu of installing and using Microsoft Windows XP Profess

This is common practice from Microsoft. From Windows XP EULA: Use of Previous Version Of Software. In lieu of installing and using Microsoft Windows XP Professional SOFTWARE, you may install, use, access, display and run ONE of the following versions: Microsoft Windows 2000 Professional, Microsoft Windows NT Workstation version 4.0 or Microsoft Windows 98 (Second Edition) (”Downgrade Software”) on the COMPUTER, provided (1) you agree that Downgrade Software support will NOT be provided hereunder by Manufacturer, MS or Microsoft Corporation, their affiliates or subsidiaries: (2) you agree that neither Manufacturer, MS nor Microsoft Corporation will provide you with the Downgrade Software or media; (3) you may not loan, rent, lease, lend or otherwise transfer the CD or back-up copy of Microsoft Windows XP Professional to another end user, except as otherwise provided in the transfer provisions of this EULA….