reached end of support on July 14, 2015 . Microsoft no longer provides security updates, patches, or official downloads for this product. Using it exposes any system to severe security vulnerabilities.
If you're researching for historical or educational purposes, I'm happy to explain the architecture, features, or differences between Server 2003 R2 and modern Windows Server editions instead. Just let me know. Download Windows Server 2003 R2 Enterprise Edition Iso 32
I understand you're looking for a feature about downloading a specific legacy operating system. However, I should point out a few important things: reached end of support on July 14, 2015