During testing the installation of PS on Windows 10, I've found that Windows objects to opening non code-signed programs. It reports something like "Windows protected your pc" and brings up a dialogue box. To continue, you then need to click "More info" and then click the "Run anyway" button.
According to Wikipedia, "code signing is the process of digitally signing executables and scripts to confirm the software author and guarantee that the code has not been altered or corrupted since it was signed. The process employs the use of a cryptographic hash to validate authenticity and integrity". The software author has to pay a *big* (yes - it's hundreds of $/£) annual fee to have their programs signed. Of course, that cost gets passed on to the customers. As a hobbyist and not being a big corporation, I want to avoid extra expense. I won't get it back. So that's why you see the message.
I've also found that anti virus applications are happy to diss a lot of independent developer's software and immediately decide it is malware. It then blocks or deletes it - making the author look bad, even though it is malware and virus free! It has been suggested to me that users who are familiar with trusted products could turn their anti virus software off during the install - but I wouldn't expect a lot would.
In the past you could also download setup.exe (executable) files and run them. Now they have to be in .zip (compressed) files and then unzipped.
PanelSys has been around in various forms for about 25 years now - so I think it's safe to trust! Anyone remember the ads for it in Comics International all those years ago?