How to make my program safe for Windows?

Question

Hello! I made a simple program for Windows, but when installing Windows says 'Windows protected your PC. Microsoft defender SmartScreen prevented an unrecognized app from starting. Running this app might put your PC at risk.'

How can I make Windows to not react like this? Not for me, but for future users of my program.
I see only one answer about Digital code signing. But it is too expensive for a free program.
Is there any other way?

Program is made using Qt.

Answer 1

This is the default behavior by the Windows and the only option is to sign your application with a valid digital certificate. Otherwise, Windows will warn user about security for unsigned applications. Another issue is the reputation of the application and as users start using it and trust it, then the algorithm will recognize it as a safe application.