Microsoft still hosts evaluation ISOs for specialized architectures, such as Windows Server 2008 R2 for Itanium-Based Systems .
Before running the installer, ensure you have prepared the system to avoid installation failures: windows 2008 r2 sp1 download
If you have a fresh installation of Windows Server 2008 R2 (pre-SP1) that is currently online: windows 2008 r2 sp1 download