No native symbols in symbol file

I am trying to remote debug a Windows Form app with VS2008.

Attaching to process works fine (Remote (Native only with no authentication)), but when I o开发者_如何学JAVApen the modules window and try to load symbols I get No native symbols in symbol file.

I realise it has something to do with how the app was build but cannot figure out what ?

If it's a Windows Forms app, that implies it's a .NET app? Then Native debugging is the wrong thing - you're not debugging Native code, but .NET code. I don't think you can debug .NET code via "No Authentication (native only)" - you're forced to use "Windows Authentication" mode.