It wouldn't have anything to do with the user's machine if you're getting a build error. That would be on your machine. Also, no offense, but this is a VB forum, not C#. You might have better luck on a forum for C#.
Don't know exactly what's causing your problem, but Pirate once posted this handy link to MSDN on deploying an app. Skip the first part, that's about making an app in the first place. Don't know if it applies to C#.