Recently I was working with a client who downloaded the retail version of SQL 2012 Standard and put it in evaluation mode. It had been meant to be a test install, but circumstances forced it into production. Sadly, the key was never changed. A short time later the key had no expired and a production server was down.
The client quickly purchased Microsoft SQL 2012 Standard from Microsoft as a Volume License. This is where the issue presented itself. Retail versions of SQL allow you to enter a 25 digit key into SQL Management Studio, however the client purchased a Volume License edition and that key is embedded in the .iso. I had no key to enter.
I did some research and was able to talk to a contact at Microsoft. I was advised to do the following:
Please run the setup from the SQL media (which contains the license key), then from the SQL Server Installation Center click Maintenance, and then select Edition Upgrade. One should see the license key embedded on Product Key page. Proceed as instructed on screen like selecting the instance for which you need to do edition upgrade.
Low and behold it worked! The license key populated itself from the .iso and I was able to successfully upgrade my client without any loss of data or further downtime.
Myke Schwartz, PEI