Application not trusted

How does an application go from not verified to not trusted. I have a program called setupwizard.exe. It is part of BeyondTV. Recently I installed a quad TV tuner card and ran this program to setup the tuners. The system is a windows 10 clean install. Today I noticed that the other tuner card was not found in device manager. After several attempts I switched the tuner card between PC's. After rebooting both systems the tuner card in each PC was found. I then tried to run the setup program and got the "This app has been blocked for your protection." So this application worked with in the last three weeks. Now it won't run. I then tried to run the setupwizard on the other PC and got the same message. I have a third system running windows 10. This system has been offline for that last couple of weeks. I booted this system up and was able to run the setupwizard with no problem. I then copied the setup wizard from the system that worked and tried to run it on the failing system. It still got blocked. I then tried to reinstall the BeyondTV program and the installer also got the blocked message. I just installed this program two weeks ago.
So the question is what changed. The only thing I can think of is a windows update. in the last two weeks.
When I ran the program on the system that was offline a pop up message asking for permission to run a not verified application. But no the pop up says not trusted.

Thanks
RAC

Hi there

some of these I'd just ignore if you trust the application -- I get these when downloading Windows versions of the nightly builds of Logitech Media server - which is a 100% safe (and useful) server music program.

Message is something like "This program isn't frequently downloaded" -- although why that should be a criterion -- after all if you do it on downloads - what about some dubious but popular programs from some torrent sites !!!.

Again if you trust your source download and the program just ignore the message and install anyway.

Cheers
jimbo

I could understand if I downloaded this program in the last week. But I downloaded this program in 2010. I've had no problem running the program until yesterday.

RAC