So nice to see that the author of the software is quick to reply to everyone’s emails (sarcastic)
I too installed the program, unchecked the 21 days and then continued. It allowed me to enter the registration number, but then my laptop wasn’t showing it on the start screen, so I ended up deleting it and re-installing it. Unfortunately this time I forgot to uncheck the 21 days and now, even though I delete the program and re-install it it won’t allow me to enter the registration key. Somehow, it’s obvious, windows is keeping some remnants of the previous installations on the system and that’s what’s bugging it.
Maybe there is nothing to do, but it would be good to have a comment back from the publisher.