The license key is located in the documents (e-mail, product packaging, etc.) that you received when you purchased.
If you have a version with this key installed, you can also do the following:
Go to the directory where you installed the software (for example, C: \ Program Files (x86) \ MatchWare \ MindView 7.0) and look for a file called sn.ini. Open it with a suitable program (for example notepad.exe = editor) and you will see something like this:
“Serial” = license key, so use this string to activate.
If you are notified that it has already been activated too many times, please send an email to firstname.lastname@example.org (stating the license key!).