The Volume license media is pre-PIDed. Hence you have to call support to get a Key when doing an in-place upgrade from the trial to licensed version.

Alternatively, Volume license media has the key buried so you can download the media and extract the keys using the following process:

1. Go to the media
2. Open up the 'AT' directory
3. Use notepad to open the setup.sdb file
4. Search for "Product Key" in that file
5. That product key can be use in TFS repair to turn TFS into a fully licensed copy

Also see the MSDN docs at: http://msdn2.microsoft.com/en-us/library/ms404852.aspx

1. Once you have the key, run setup and enter the product key for the MSDN AA edition of TFS.
2. Downtime should be short ~ 5 minutes.