@Ponch: Thanks for correction! I do many language errors, thanks for anyone correct me ! @mikesw: Nothing to do with AES algorithm ! It's just a basic conversion. This method is used for Windows because there are keys preactivated with hardware, but for Office there isn't preactivated license, so if you use license many times you will be in illegal status, but I think you could find a vbs script to get your Office license. There are many softs like Everest which get all licenses of your system ...