Downloading Executable: Warnings

I have a website based on WordPress. On this website, I provide a link to download my windows-based application setup (which is an executable - can be either a .exe or a .zip). In both cases, when someone downloads these programs, the target computer (doing the download) issues warnings that are pretty scary for the user (something like “warning! these files are not commonly downloaded”. Is there a way to prevent these warnings from scaring users away?

Code signing.