By default, when SCOM 2012 R2 is installed, it uses an eval license (hence the yellow warning when you install the management server). When you go to the “Administration” workspace there is a center page link to technet to “Upgrade SCOM to full version”.
Here’s the simple way to add that product key from powershell.
set-SCOMLicense -ProductId “insert product key here”
stop-service cshost; stop-service omsdk; stop-service healthservice
start-service cshost; start-service omsdk; start-service healthservice
Alternatively, you can reboot the management server.
After that, to verify the key is install you can take the following steps.
Launch the Operations Manager Console > Go to “Help” and click “About” > Next to the Version information it should now say Retail. *Note that it’s okay if the Product ID is blank.
I hope this makes your day at least a little bit easier.