Why does Windows UAC icon appear for my program on some PCs but not others?

Question

I have recently noticed that an application we have developed has the windows UAC icon next to it on some of our customers' PCs but not ours. Is there any reason why this might happen?

The reason I noticed this is that the customer claims that the software has suddenly stopped working, and when inspecting their PC I noticed that the UAC 'shield' is on our application's icon - I've never seen this before and it certainly isn't there when I install it on my PC, so I'm wondering if any changes to their PC may have caused this, and if this could be related to why the application has stopped working?

Answer 1

If anyone's interested, here was the cause of, and solution to, the problem.

Somehow the client had told the program to run as administrator at all times, which is what brought up the UAC message, and somehow stopped it from working properly (an external Excel worksheet was supposed to be communicating with it via a DLL, which is what stopped working).

To turn this mode off, I right-clicked on my application executable, clicked properties > compatibility and unchecked the 'Run this program as an administrator' checkbox. This immediately solved the problem. You could also use the 'Change settings for all users' dialog to change this setting for multiple users.