Windows Server 2003 was delivered with only one product key. When you obtain Windows Server 2008 from an OEM or as an FPP, you receive two product keys to use to activate the software. The product keys in Windows Server 2008 are called the product key and the virtual key.
Product key
The product key is a 25-character key. You use this key to activate an instance of Windows Server 2008 in the physical operating system environment in which the instance of Windows Server 2008 is not running on any virtualization software or on a hypervisor layer.
Windows Server 2008 uses the product key to associate or bind itself to the server hardware exactly as it does in Windows Server 2003.
If the server came from an OEM with Windows Server 2008 preinstalled, the OEM may have pre-activated the instance of the software in the physical operating system environment. When you use a product key, a reactivation is required in the following scenarios:
- You significantly change the hardware configuration of the server on which Windows Server 2008 is running.
- You try to move an instance of Windows Server 2008 from one physical computer to another.
Virtual key
The virtual key, also known as a virtual product key, is also a 25-character key. You use this key to activate an instance of Windows Server 2008 in a virtual operating system environment in which the instance of Windows Server 2008 is running on virtualization software or on a hypervisor layer.
Windows Server 2008 uses the virtual key to bind to the hardware differently than in Windows Server 2003 and differently than it does when it is activated by using the product key.
You can use a virtual key to change most of the virtual hardware configurations that typically vary in virtual operating system environments, such as memory or CPU. You can do this without having to reactivate. Additionally, you can use the virtual key to move instances of Windows Server 2008 from one virtual environment to another without having to reactivate.
The virtual key lets you activate multiple instances of Windows Server 2008 in virtual environments. This provides better support for the license terms that enable you to perform the following functions:
- Create and store any number of instances of Windows Server 2008 (depending on the edition)
- Run multiple instances of Windows Server 2008 in a virtual operating system environment at the same time
The following table lists the number of instances per license that you can run at the same time in a virtual operating system environment.
| Windows Server 2008 edition | Virtual operating system environment instances |
|---|
| Standard | 1 |
| Enterprise | 4 |
| Datacenter | any number |
| Itanium | any number |
- In Windows Server 2008 Standard Edition and in Windows Server 2008 Enterprise Edition, you can use the instance that is running in the physical operating system environment only to manage the virtual instances if you are running the maximum number of instances in the virtual operating system environment.
- The activation experience and the user interface are the same with either product key.
- All OEM and FPP editions of Windows Server 2008 come with two product keys. All editions require activation. In Windows Server 2003, editions that were designed for Itanium-based systems did not require activation.
- OEMs can pre-activate Windows Server 2008. However, pre-activation is supported only in the physical operating system environment.
The virtual key cannot be preinstalled by an OEM. You must activate virtual instances of Windows Server 2008.