You can use DISM.exe to upgrade the Windows Server 2008 R2 Edition you have installed from the command line. Before going any further, don’t think about doing this on DC or Exchange Server without first removing these roles.
Why would you need this? I’m working with a Virtual Data Centre provider who provide a Windows Server 2008 R2 Standard Edition template, but I need Windows Failover Clustering support for Exchange Server 2010 Database Availability Groups.
I could use the install media, but using DISM.exe is much simpler. You may run in to trouble if a single licence key covers both Standard and Enterprise, in that case head over to http://technet.microsoft.com/en-us/library/ff793406.aspx and use a KMS client setup key to perform the upgrade.
Run the following from the command prompt, followed by a restart as directed.
DISM /online /Set-Edition:ServerEnterprise /ProductKey:ABC12-ABC12-ABC12-ABC12-ABC12
If KMS client setup key was used remember to change to the key.
Daniel Noakes