in your computer, in the same local you intalled the software (in my case is ScanMaster-ELM v2.1) there is a ZIP file with name "KeyGen.ZIP". You need to extract the file .EXE and open this software.
After that, you have to open the ScanMaster-ELM software, and then, will open a screen inform you a code. You need to take this code and insert in the KeyGen screen software. Then click in the "Generate Key" button. So you take the key and insert in the Scan Maester software to open this.