If I have a class library with an app.config file (I know it\'s not ideal, just bear with me for a moment) which has settings values created by using the projects S
Edited after reading comments.
I think I see what your after. The My.Settings will used the compiled values from your class libs settings as default values. I believe these are compiled in. You can reflect the source though to see if it is setting a defaultvalue attribute on them.
You can override these by setting the values in the main exe's application file. If the settings aren't in the exes file, then you will use the default ones you specified in your class libs.
You shouldn't care about the file name. Just assume the settings are either defaulted or were overridden. If you need to know if they were overridden, that's another issue.