Retrieving Your Exchange Server 2003 License Key
Written by Sam McGeownThis article is now 18 years old! It is highly likely that this information is out of date and the author will have completely forgotten about it. Please take care when following any guidance to ensure you have up-to-date recommendations.
Recently I found the need to retrieve the key from an existing Exchange Server for a reinstall - the software is legally licensed but the key was somehow lost. A trawl through my registry revealed that the key is stored in an obscure place: