| Windows Server 2008 Web Edition | Windows Server 2008 Standard Edition | Windows Server 2008 Enterprise Edition | Windows Server 2008 Datacenter Edition |
| Supersedes | Windows Server 2003 Web Edition | Windows Server 2003 R2 Standard Edition
Windows Server 2003 R2 Standard x64 Edition | Windows Server 2003 R2 Enterprise Edition
Windows Server 2003 R2 Enterprise x64 Edition | Windows Server 2003 R2 Datacenter Edition
Windows Server 2003 R2 Datacenter x64 Edition |
| Hyper-V virtualization technology | Not included | Included1 | Included1 | Included1 |
| OS instances permitted per server license | One instance (physical or virtual) | One physical instance plus one virtual instance2 | One physical instance and up to 4 virtual instances2 | Unlimited number of OS instances |
| Maximum server RAM supported 3 | 32-bit: 4GB
64-bit: 32GB | 32-bit: 4GB
64-bit: 32GB | 32-bit: 64GB
64-bit: 2TB | 32-bit: 64GB
64-bit: 2TB |
| Maximum number of CPUs | 4 | 4 | 8 | 64 |
| Hot swap RAM and CPUs | No | No | No4 | Yes |
| Cluster Service (failover) | No | No | Yes, up to 16 nodes per cluster | Yes, up to 16 nodes per cluster |
| Terminal Server | No | Yes5 | Yes | Yes |
| Network Access Protection | No | Yes6 | Yes | Yes |
| U.S. estimated retail price 7 | US$470 per server ( available only without Hyper-V) | US$800 per server
(US$772 without Hyper-V) | US$3,000 per server
(US$2,972 without Hyper-V) | US$3,000 per processor
(US$2,972 per processor without Hyper-V) |
| CALs or External Connector required 8 | No | Yes | Yes | Yes |