ClickOnce open file security warning in certified application

Question

My ClickOnce WPF 4.0 application can be downloaded and installed locally. The prerequisite installer and the executable file of the application itself are signed by Comodo. There is no "Unknown publisher" prompt. This works great so far.

But users still get a "Open File - Security Warning" from Windows telling them the file is downloaded from the internet (mentioning me as publisher). Shouldn't this be already addressed with the certification? It really diminishes trust in my application since its shown on every start as long as the user doesn't uncheck the CheckBox "Always ask before opening this file".

Answer 1

The prompt did disappear after some time so I thought it to be a glitch of Windows 8 like Ricky assumed. But when I had to update my certificate I had the same problem again, this time with Windows 8.1. It took some days but finally it doesn't occur any more.

I assume the reputation of the application has increased to a level where it no longer needs to show the prompt.