Here’s a brief write-up on the —strictly for educational and historical context. Windows XP Professional RTM: A Note on Product Keys Background Windows XP Professional RTM (Release to Manufacturing) was the original version of Windows XP, released in August 2001. RTM means the code was finalized and sent to disc manufacturers, predating retail availability.
RTM product keys follow the standard 25-character format used by Windows XP, grouped as five blocks of five alphanumeric characters: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX windows xp professional rtm product key