From your description, it seems that sometimes Couatl doesn't start, which will also result in all products in Trial. If it doesn't start when the simulator starts, I'm fairly sure it's the antivirus. Less likely, but still possible, an issue with the VC++ runtimes, sometimes a Windows restart is required after a Live Update.
If, instead, it starts with the sim, but doesn't RESTART, than it's likely another issue.