If you wish to "downgrade" your Windows XP Upgrade Licenses to a prior operating system license, you may do so by following this procedure:
1) Order one Windows XP upgrade license for each computer that requires it (up to 50 total).
Your license authorization number and installation keys will arrive via email. Once assigned, you will also be able to access them by logging in to your TechSoup account at http://www.TechSoup.org/Stock and clicking on "Order Status" on the left-hand purple bar.
2) Contact Microsoft Worldwide Fulfillment (WWF).
Phone: (800) 248-0655 Fax: (800) 554-8281
Explain to the representative that you have ordered [number] of Windows XP Upgrade Licenses from TechSoup Stock, and you wish to "downgrade" them so that you can install Windows [98, 2000] instead. You would like to order a CD of this preferred operating system.
You will be asked for your license authorization number and installation keys. World Wide Fulfillment will then send you a copy of the operating system media and provide the appropriate number of license keys. Please note: You will be charged a one-time $27 shipping & handling fee by Microsoft.