I have a project which is only for use on Windows (several versions of Windows, but not Mac). I am trying to get a nice built in modal dialog box to use for various purposes in my Unity program. Is this possible? I have tried the obvious (to me) which is using System.Windows.MessageBox.Show(), but it will not allow that, saying: 'Windows' is not a member of 'System'. Is there another way to do this? I would really prefer not to use Unity's GUI to make all these dialogs, since I really want them themed to match the user's system. I do not want to build custom dialogs that will be non-standard-looking. I want people with XP to see an XP dialog and Vista to see a Vista dialog. Is this possible or am I doing something wrong?