Back in the ‘old days’ there were , just as right now, different version of Windows Server.
Whenever you installed the Enterprise Edition and realized you should have chosen DataCenter edition, you would need to do a re-install of the operating system.
Very, very annoying…
Then Windows Server 2008 R2 was introduced Open-mouthed smile
One of its may improvements was the ability to ‘upgrade’ your Windows edition within having to re-install the entire operating system.
Instead, you could do this with a simple commandline where you use the tool called DISM which is part of the operating system since Windows Server 2008 R2.
The supported upgrade paths for Windows Server 2008 R2 are:
- Windows Server 2008 R2 Standard -> Windows Server 2008 R2 Enterprise -> Windows Server 2008 R2 Datacenter
- Windows Server 2008 R2 Standard Server Core -> Windows Server 2008 R2 Enterprise Server Core -> Windows Server 2008 R2 Datacenter Server Core
- Windows Server 2008 R2 Foundation -> Windows Server 2008 R2 Standard
So, howto do the actual upgrade? Easy 
PS C:\Users\Jeff> dism /online /get-currentedition Deployment Image Servicing and Management tool Version: 6.1.7600.16385 Image Version: 6.1.7600.16385 Current edition is: Current Edition : ServerEnterprise The operation completed successfully. PS C:\Users\Jeff> dism /online /get-targeteditions Deployment Image Servicing and Management tool Version: 6.1.7600.16385 Image Version: 6.1.7600.16385 Editions that can be upgraded to: Target Edition : ServerDataCenter The operation completed successfully. PS C:\Users\Jeff> dism /online /Set-Edition:ServerDataCenter /ProductKey:74YFP-3QFB3-KQT8W-PMXWJ-7M648 Deployment Image Servicing and Management tool Version: 6.1.7600.16385 Image Version: 6.1.7600.16385 Starting to update components... Starting to install product key... Finished installing product key. Removing package Microsoft-Windows-ServerEnterpriseEdition~31bf3856ad364e35~amd64~~6.1.7601.17514 [==========================100.0%==========================] Finished updating components. Starting to apply edition-specific settings... Restart Windows to complete this operation. Do you want to restart the computer now (Y/N)?
Note that in this post I’ve used the KMS Client Setup Key. These keys can be found here: http://technet.microsoft.com/en-us/library/ff793421.aspx
