How to Tell What Type of Windows XP CD or License Key You Have @Technibble
 

*Source: Technibble (http://www.technibble.com/how-to-tel...ey-you-have/)*
___________
For the not-so-techie readers, not all Windows XP CDs and Licenses are the same. There are many different types of Windows XP CDs available:

OEM - Which are usually sold with the computer
Retail - Brought stand alone in stores like BestBuy, CompUSA etc..
Upgrade - To upgrade from a previous operating system
Branded - Specifically branded copies from large computer manufacturers like Dell
Action pack - Was part of the Microsoft Action Pack
Volume License - Typically used in large businesses, government and educational institutions

More...