JSI Tip 8993. How to determine the channel that your copy of Windows Server 2003 was obtained through?

Microsoft Knowledge Base Article 889713 contains the following introduction:

This article describes how to determine the channel that your copy of Microsoft Windows Server 2003 was obtained through. This article also describes the characteristics that distinguish the product when it is obtained through these different channels. The channels include the following:

• Retail 
• Evaluation 
• Volume licensing programs 
• OEM 
• Checked build