Standalone Internet Access Errors

[Dan Friedman]

I have a standalone app that users download, unzip, and run.   This works fine.  However, from time to time I get a call from a customer, typically on a windows computer, that the app is unable to reach the internet.  My standalone is getting timeout errors, and "Host address not found" messages when trying to access the internet.  Usually, disabling security settings on the users computer will resolve the problem.  But, now and then that doesn't work or they can't find the service on their system that is blocking my app.  I know it's not a url or domain issue because the very website the app it trying to reach is the same server they downloaded the app.  I think the issue is that the app it's self is being blocked.  I wonder if it's because it's not being installed by a MSI installer and therefore is untrusted.  I'm not a windows expert by any means and am a bit perplexed.  Does anyone have any knowledge of this or have any advice?

Any thoughts are appreciated!

-Dan