Ok, that's proper Trial mode, indicating everything is fine with the software, which is clearly running correctly. It might have been worse if the software didn't run, something that many users confuse with Trial mode, because they don't see anything. So, firewall or antivirus doesn't have anything to do with your problem.
It seems something must have tricked an hardware change.
We don't try to do any hardware detection on our own, we rely on Esellerate or Soraco (they are both running now, until Esellerate will close at the end of September, so it will be removed from our software too) so, if one of them is telling the hardware changed, we don't have any choice than trust it has.
Now, sometimes updating some drivers, or the bios, might result in an hardware change, because even Esselerate or Soraco don't really try to check the hardware directly. They rely on certain Windows API calls that returns the hardware ID to them. Some users noticed updating the BIOS, or changing some drivers, usually the network drivers, might result like an hardware change.
The question is, of course, are you able to reactivate normally ?