Many users download the standard Windows Server 2003 SP2 ISO and miss the "R2" features. If your ISO does not require a second disk, you do not have R2. Here is what R2 adds:
SP2 is a cumulative update that improved security, stability, and added support for WPA2 wireless security and the Scalable Networking Pack (SNP). System Requirements Windows Server 2003 Enterprise R2 Sp2 Iso Download
Features include Active Directory Federation Services (ADFS) for identity management and improved Distributed File System (DFS) for branch office efficiency. Many users download the standard Windows Server 2003
If you're still using Windows Server 2003 in your organization, you might need to download the Enterprise R2 Sp2 ISO file for various reasons: Windows Server 2003 Enterprise R2 Sp2 Iso Download