Let me start by saying that I am definitely not a fan of “in-place” upgrades. However, there are scenarios where you simply must choose this option. Before summarizing what is supported, it’s a good idea to go over what is not supported.
Unsupported Upgrade Scenarios
- Windows 9x, Windows Millennium, Windows XP, Windows Vista Editions, or Windows 7
- Windows NT Server 4.0
- Windows 2000 Server
- Windows Server 2003 (RTM & SP1), Windows Server 2003 Web
- Windows Server 2003 for Itanium-based Systems
- Windows Server 2008 R2 (M3 or Beta)
- Windows Server 2008/2008 R2 for Itanium-based Systems
- Cross-architecture in-place upgrades (x86 –> x64)
- Cross-language in-place upgrades
- Cross-edition upgrades (Foundation –> Datacenter)
- Cross-build type in-place upgrades
Supported Upgrade Scenarios
From Server 2003 (SP2, R2) –> Server 2008 R2
- Standard –> Standard, Enterprise
- Enterprise –> Enterprise, Datacenter
- Datacenter –> Datacenter
From Server 2008 (SP1, SP2) –> Server 2008 R2
- Web –> Web, Standard
- Web Core –> Web Core, Standard Core
- Standard –> Standard, Enterprise
- Standard Core –> Standard Core, Enterprise Core
- Enterprise –> Enterprise, Datacenter
- Enterprise Core –> Enterprise Core, Datacenter Core
- Datacenter –> Datacenter
- Datacenter Core –> Datacenter Core
