I've come across a problem where a contractor has installed SQL 2008 R2 evaluation version instead of using my volume licence key installation. I found out how to extract the key from the VLK version and tried to put it into the evaluation version but it says it is the wrong version. I have a number of databases running on that server and I don't really want to back up all of them, export users, maintenance tasks, etc., and have to uninstall SQL and reinstall the correct version and restore them all again.
Is there a way of running the VLK installer to "upgrade" the evaluation version to the correct version? Are there any command line switches I can run the setup.exe with to ensure it does the upgrade correctly?