I have a server machine with Windows 2008 Web Server running on it and I THINK I have been running it under the TechNet license. Now I need to turn it into a production server and I need to find out if I really am running it under a TechNet license so that I can upgrade it. But I can't seem to be able to check which license I am running the OS under. Is there a way to check this?
Do you still have access to the Technet account? If so, just compare the license numbers from your installation and the license list from Technet.
To get the key of your installation, you could use a tool like KeyFinder.