While I've outlined in the forums on how to deactivate your product, in the event that you get the error that says " key is already used " please visit the Chessbase website at http://en.chessbase.com/support and supply your serial code. Under the game list choose Deep Fritz 14. Explain to them your activation limit has been exceeded and they will look at your issue and extend your activation count on a case by case basis. Remember to use the deactivate button when you plan on reformatting your computer or moving the game to another one Thank you, Jason Carver Community Support at Encore Software / Viva Media